AA092 584 COASTAL ENGINEERING RESEARCH CENTER FORT BELVOIR VA F/B 6/6

AN ANNOTATED BIBLIOGRAPHY OF SEAGRASSES WITH EMPHASIS ON PLANTI-ETC(U)

SEP 80O 0 BKNIGHT, P L KNUITSON, E .J PULLEN

UNCLASSIFIED CERCMR807M "' uunllnllnIml

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MICROCOPY RE~SOLUTION TEST CHART
'"MR 80-7

An Annotated Bibliography of Seagrasses

with Emphasis on

Planting and Propagation Techniques

by

00 Daniel B. Knight, Paul L. Knutson, and Edward J. Pullen

MISCELLANEOUS REPORT NO. 80-7

SEPTEMBER 1980

A'NQ

SDECi8 1980

Approved for public release;

distribution unlimited.

U.S. ARMY, CORPS OF ENGINEERS

~ COASTAL ENGINEERING

RESEARCH CENTER

lJJ Kingman Building

Fort Belvoir, Va. 22060

80 1 0 08 -04 9
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Reprint or republication of any of this material

shall give appropriate credit to the U.S. Army Coastal

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Limited free distribution within the United States

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National Technical Information Service

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The findings in this report are not to be construed

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47T_1ITLI -fenS. Tu~W-yYPE OFgRf.A PERIOD COVERED

N 4NNOTATED AIBLIOGRAPHY OF EAGRASSES WITH M~)iscellaneous /eportob

L PfrASIS ON PUNTING AND PROP ATION TECHNIQUES,6pWoIW A.RPiIWK

7.A S. CONT-RACT OR GRANT NUMBERW.

)-uanie1 B./Knight,-Paul L./Knutson'

jaLEdward J./Pullen -.. ... 0)'i

9. PERFORMING ORGANIZATION NAME AND ADDRfSS 10. PROGRAM ELEMENT, PROJECT. TASK

Department of the Army AREA & WORK UNIT NUMBERS

Coastal Engineering Research Center CCERRE-CE) G31632

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11. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT OATE

Department of the Army It/1 September 198,0

Coastal Engineering Research Center 13. NUMBER OfPAG" -

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IS. SUPPLEMENTARY NOTES

19. KEY WORDS (Continue an reverse aide if necesaryv and Identify by block nuimb er)

Annotated bibliography Propagation techniques

Planting techniques Seagrasses

2@" \APSTVI ACT (Cethmu -m evere sb of neremy mo identifty Ay block nubet)

4This bibliography includes abstracts on 145 historic and recently published

research reports on seagrasses, with emphasis on Halodule, Ruppia, Thalassia

and Zostera. The compilation of reports emphasizes planting and propagation

techniques for seagrasses and important environmental parameters for

successful transplanting. The bibliography is published to aid coastal

engineers and scientists in planning, designing, and transplanting seagrasses

to rehabilitate areas affected by coastal engineering projects and to

stabilize substrates adjacent to navigation channels.,*-

Do 1 0 3 too-now or I wOV IS SOSSLETE :

SECURITY CLASSIFICATIONV OF THIS PAGE (Whlen Daea frntered
PREFACE

This report is published to provide coastal engineers and scientists a

comprehensive annotated bibliography on seagrasses with emphasis on planting

and propagation techniques. The compilation of the bibliography was carried

out under the coastal ecology research program of the U.S. Army Coastal

Engineering Research Center (CERC).

The report was compiled by Daniel B. Knight, Paul L. Knutson, and Edward

J. Pullen of the Coastal Ecology Branch, under the general supervision of R.P.

Savage, Chief, Research Division.

Comments on this publication are invited.

Approved for publication in accordance with Public Law 166, 79 th Congress,

approved 31 July 1945, as supplemented by Public Law 172, 88t h Congress,

approved 7 November 1963.

ED E. B SH

Colonel, Corps of Engineers

Commander and Director

NTI3 GPA&I

DTIC TAB

USe in' 0 lit

P :, ' ,~"
CONTENTS

Page

CONVERSION FACTORS, U.S. CUSTOMARY TO METRIC (SI) .................... 5

I INTRODUCTION ............................................................ 7

II USE OF THE BIBLIOGRAPHY ................. ........... .............. 7

III ANNOTATED BIBLIOGRAPHY ................ ......................... 7

IV KEYWORD INDEX ........................ . ................. ....... 44

4
CONVERSION FACTORS, U.S. CUSTOMARY TO METRIC (SI) UNITS OF MEASUREMENT

U.S. customary units of measurement used in this report can be converted to

metric (SI) units as follows:

Multiply by To obtain

inches 2S.4 millimeters

2.54 centimeters

square inches 6.452 square centimeters

cubic inches 16.39 cubic centimeters

feet 30.48 centimeters

0.3048 meters

square feet 0.0929 square meters

cubic feet 0.0283 cubic meters

yards 0.9144 meters

square yards 0.836 square meters

cubic yards 0.7646 cubic meters

miles 1.6093 kilometers

square miles 259.0 hectares

knots 1.852 kilometers per hour

acres 0.4047 hectares

foot-pounds 1.3558 newton meters

millibars 1.0197 x 10- 3 kilograms per square centiowter

ounces 28.35 grams

pounds 453.6 grams

0.4536 kilograms

ton, long 1.0160 metric tons

ton, short 0.9072 metric tons

degrees (angle) 0.01745 radians

Fahrenheit degrees 5/9 Celsius degrees o7 Kelvins1

ITo obtain Celsius (C) temperature readings from Fahrenheit (F) readings.

use formula: C - (5/9) (F -32).

To obtain Kelvin (K) readings, use formula: K - (5/9) (. -32) + 273.1S.

5
AN ANNOTATED BIBLIOGRAPHY ON SEAGRASSES WITH

EMPHASIS ON PLANTING AND PROPAGATION TECHNIQUES

by

Daniel B. Knight, Paul L. Knutson, and Edward J. Pullen

I. INTRODUCTION

Seagrasses are valuable resources to the coastal marine ecosystem, and

coastal engineering activities have created impacts which adversely affect

these resources. This annotated bibliography is published to assist coastal

engineers and scientists in planning, designing and transplanting seagrasses

to restore areas changed by coastal engineering projects, and to stabilize

substrates adjacent to navigation channels. The report includes both the historic and the recent research published on transplanting seagrasses. Some of

the citations were obtained from previously published literature reviews

(Phillips, 1964; McRoy and Phillips, 1968; Zieman, Bridges, and McRoy, 1978;

Jones and Schubel, 1978). This intensive review emphasizes the genera

Halodule, Ruppia, Thalassia, and Zostera.

II. USE OF THE BIBLIOGRAPHY

Entries in the bibliography are arranged alphabetically by author or source

and reference number. Most entries include the source information and a short

abstract. A keyword index by reference number is also provided.

To search a given topic, refer to the keyword index and locate the term

that best describes the subject. For example, if the keyword is Thalassia,

then all references listed under Thalassia should be reviewed. If references

on more specific topics are required, a combination of keywords may be used.

For example, if information on "planting methods of Thalassia" is desired,

then references which appear under both keywords (planting methods and

Thalassia) need to be checked.

Since some references may be listed under only one of several clos'e1

related keywords; it is advisable to check many potential keyworic co ensure

complete coverage on a particular subject.

Some references were not located for review but, because of their reference

to seagrass planting and propagation, were cited. Keywords for these p~blications were taken from their titles.

III. ANNOTATED BIBLIOGRAPHY

1. ADAMS, S.M., "The Ecology of Eelgrass, Zoetera marvina (L), Fish Comi..-

nities. I. Structural Analysis," JournaZ of Experimental Ma-efnl Biology

and Ecology, Vol. 22, No. 3, June 1976, pp. 269-291.

Fish populations in eelgrass (Zoetera marina) beds in two diflerent estuarine areas (Phillips Island and Bogue Sound) near Beaufort, Nrth Carolina,

were compared to determine aspects of their community structire. The fish

communities were characterized by low diversity and high standing crops of

biomass and energy, both of which showed seasonal variation. fide temperature

fluctuations related to the overall shallowness of the beds plobably regulated

the diversity of fishes utilizing the beds. The communities were dominated by

pinfish (Lagodon rhombiodes), which comprised 45 and 67 percent of the fish

biomass in the Phillips Island and Bogue Sound beds, respeczlvely.

7 n PI
Changes in total body caloric content were probably related to developmental stages and changes in diet. Adult fish often had significantly higher

weight-specific caloric contents than juvenile fish. Monthly or seasonal

variations in caloric content of the organic matter of pinfish had little

influence on the caloric content within the various sizes of the fish.

Correlation was significant between fish biomass, temperature, and Zostera

biomass. Fish biomass was highest when temperature and grass biomass were at

a maximum. In general, water depth over the beds had little effect on the

standing crop of fish within the bed, but cooler waters which occurred at

night had a large effect.

2. ADAMS, S.M., "The Ecology of Eelgrass Zostera marina (L), Fish Communities. II. Functional Analysis," Journal of Experimental Marine Biology and

Ecology, Vol. 22, No. 3, June 1976, pp. 293-311.

Production and respiration of fish communities in two eelgrass beds in two

different shallow estuarine systems (Phillips Island and Bogue Sound) near

Beaufort, North Carolina, have been estimated for 1971-72. Annual production

was 21.7 kilocalories per square meter in each bed. Pinfish accounted for 45

and 68 percent of the production in the Phillips Island and Bogue Sound beds,

respectively. Annual community respiration was 57.9 and 69.7 kilocalories per

square meter in the two beds, with pinfish accounting for 62.6 and 26.7 percent of the total in the Bogue Sound and Phillips Island beds, respectively.

Estimation of the annual food energy consumed by the eelgrass fish community

using the Winberg and daily ration methods gave values within 6 percent of

each other.

Energy turnover was high (2.8), and the efficiency of energy dissipation

low for the two eelgrass fish communities. High ecological efficiencies of

0.24 and 0.23 and the high overall efficiency of the eelgrass system

(production-solar radiation) of 0.0051 and 0.0086 percent indicate that the

eelgrass beds are efficient systems for converting consumed energy and solar

radiation into fish biomass.

3. ADAMS, S.m., "Feeding Ecology of Eelgrass Fish Communities,"Transactions of

the American Fishertes goeiety, Vol. 15. No. 4, July 1976, pp. 514-519.

The principal foods of tishes from eelgrass (Zostera mrina) beds in

shalloWwater estuaries near Beaufort, North Carolina, were detritus, planktonic coiepods, and epifaunal crustaceans. Foods produced within the eelgrass

beds (e.6., crustaceans, gastropods, and detritus) probably accounted for

about 56 Prcent by weight of the diet of the eelgrass fish communities.

Pinfish *Zagodon hombiodes) under 35 millimeters fed primarily on planktonic copepcds, thereafter detritus gradually replaced copepods. Pinfish

about 70 millimeters long became more omnivorous and consumed a greater proportion of plait material and polychaete worms. Changes in feeding habits may

have been resonsible for significant differences in the weight-specific

caloric contents observed between three size groups of pigfish and pinfish.

Only one species fed in the seagrass beds at night, but biomass of all fish

was twice as higi at night than in the day.

The eelgrass fish communities are not food-limited because the total annual

food production in the beds is greater than the total annual food consumption

by the macrofauna.

8
4. ADDY, C.E., "Eelgrass Planting Guide," Maryland Conservationist, Vol. 24,

1947, pp. 16-17.

This report discusses transplanting methods, planting stock, planting

areas, planting times, and planting methods for seeds.

5. ADDY, C.E., "Germination of Eelgrass Seed," Journal of wildlife Management,

Vol. 11, No. 3, July 1947, p. 279.

Methods of harvesting eelgrass (Zostera marina) seed are discussed. Fruiting stems of Zostera, with spathes containing seeds, are pulled up in

August. These are placed in a box which is then anchored to the bottom of a

salt creek, allowing the spathes to decompose and release the seed. Seeds can

be stored during the winter between layers of sand in a box anchored to the

bottom of a salt creek.

6. ANDERSON, R.R., "The Submerged Vegetation of Chincoteague Bay," Assateague

Ecological Studies, Chesapeake Biological Laboratory Reference No. 446,

Natural Resources Institute, University of Maryland, College Park, Md.,

1970, pp. 106-155.

Submerged plants are important to the marine environment because of their

soil binding roots and foliage which provides food and shelter for marine

fauna. In the Chincoteague Bay area, Zostera marina (eelgrass) and Ruppia

ma' tirtz (widgeongrass) are the dominant submerged aquatic species. A 2-year

study was conducted on the distribution and primary production of these

species. Recommendations are also given for future dredging operations.

7. ANDERSON, R.R., "Submerged Vascular Plants of the Chesapeake Bay and Tributaries," Chesapeake Science, Vol. 13, No. 4 (supp.), Dec. 1972, pp. 587-

589.

This article provides a summary of the taxonomy, distribution, abundance,

and biology of submerged vascular plants in the Chesapeake Bay and its

tributaries.

8. ANDERSON, R.R., "Tentative Outline for Inventory of Submerged Aquatic Vascular Plants: Ruppia maritima, (L.) (ditchgrass)," Chesapeake Science, Vol.

13 (supp.), Dec. 1972, pp. 172-174.

This report provides a key to the identification of Ruppia maritia.

9. AUSTIN, C.B., and THORHAUG, A., "The Economic Costs of Transplanting Seagrasses: Thalassia," Proceedings of the Fourth Annual Conference on the

Restoration of Coastal Vegetation in Florida, Hillsborough Community

College Environmental Study Center, Tampa, Fla., May 1977, pp. 70-75.

Costs of planting Thalassia seeds were determined for nursery and field

planting operations. Planting is the most expensive field operation, at $0.31

per seed (1976 cost). Field collecting cost is $0.11 per seed, and nursery

planting cost is $0.06 per seed. The planting phase accounts for two-thirds

of direct costs of Thalassia bed creation.

9
10. BARILOTTI, D.C., and BACKMAN, T.W., "Irradiance Reduction: Effects on

Standing Crops of the Eelgrass, Zostera marina, in a Coastal Lagoon,"

Marine Biology, Vol. 34, No. 1, Jan. 1976, pp. 33-40.

Abundance of the eelgrass (Zostera mar'ina) in a coastal lagoon in southern

California was found to correlate with the level of irradiance at depths

greater than 0.5 meter below tidal datum. Field experiments during a 9-month

study, using canopies to reduce illuminance by 63 percent, confirmed that

turion density is a function of the irradiance the plants receive. By day 18

of the experiment, turion density in the shaded experimental areas had

decreased. Turion densities were continually lower throughout the study

period in the experimental areas. Flowering was also inhibited by shading.

The biological implications are discussed with respect to seasonal changes in

incident solar radiation, water transparency, and changes in water quality.

11. BAYLEY, S., et al., "Changes in Submerged Aquatic Macrophyte Populations

at the Head of Chesapeake Bay, 1958-1975," Estuar'ies, Vol. 1, No. 3, Sept.

1978, pp. 171-182.

Submerged aquatic plant populations in the Susquehanna Flats of the

Chesapeake Bay were monitored for 18 years. An exotic species, Eurasian water

milfoil (Myriophullum spicatum), increased dramatically from 1958 to 1962;

dominant native species declined. After 1962, milfoil populations declined

and the native rooted aquatics began to return to their former levels. In the

late 1960's all species declined and by 1972 almost disappeared from the

Susquehanna Flats. These fluctuations may have been related to several factors in the Chesapeake Bay, including tropical storms, turbidity, salinity,

and disease. The use of the flats by waterfowl is related to the abundance

and species composition of the submerged macrophytes.

12. BIEBL, R., and McROY, C.P., "Plasmatic Resistance and Rate of Respiration

and Photosynthesis of Zostera marina at Different Salinities and Temperatures," Marine Biology, Vol. 8, No. 1, Jan. 1971, pp. 48-56.

Zostera marina (eelgrass) was studied at the Izembek Lagoon, Alaska

Peninsula. Two morphologically different forms, tidepool and subtidal, were

distinguished. Both showed a high tolerance to different salinities and temperatures. The plasmatic resistance was found in a range of distilled water

up to 3.0 seawater (24 hours) and between -6* and 340 Celsius (12 hours).

Within these resistance limits, photosynthesis, which has its maximum in 1.0

(normal) seawater, decreased nearly to zero in distilled water and in 2.0

seawater, and increased with the temperature in the tidepool form up to 350

Celsius, but in the subtidal form up to 300 Celsius only. At higher temperatures photosynthesis declined sharply in both forms. Respiration was minimum

in distilled water at 00 Celsius, and increased with increasing salinity and

temperature.

13. BOONE, C.G., and HOEPPEL, R.E., "Feasibility of Transplantation, Revegetation, and Restoration of Eeelgrass in San Diego Bay, California," Report

No. WES-MP-Y-76-2, U.S. Army Engineer Waterways Experiment Station,

Vicksburg, Miss., Feb. 1976.

Several methods of eelgrass (Zostera rrtina) transplantation, restoration,

and revegetation in San Diego Bay, California, are evaluated. A literature

10
survey and current state-of-the-art eelgrass transplant methodologies are presented. Two transplanting methods are recommended; however, since neither of

these has been tested in a large-scale field program, a preliminary pilot

transplant study is also recommended. Estimated transplantation costs for

each method are also presented.

14. BOURN, W.S., "Sea-Water Tolerance of Ruppia maritima L.," Boyce Thompson

Institute for Plant Research, Yonkers, N.Y., Vol. 7, 1935, pp. 249-255.

15. BROOK, I.M., "Comparative Macrofaunal Abundance in Turtlegrasses (Thalassia testudinum) Communities in South Florida Characterized by a High Blade

Density," Bulletin of Marine Science, Vol. 28, No. 1, Jan. 1978, pp.

212-217.

Five high density Thalassia communities (>3,000 blades per square meter),

four in South Biscayne Bay and one at Murray Key in the Everglades National

Park, Florida, were sampled by suction dredge in April 1973. Macrofaunal

abundance ranged from 292 to 10,728 individuals per square meter. It is

postulated that a high standing crop of seagrass may not be the primary determining factor in faunal abundance.

16. BURKHOLDER, P.R., and DOHENY, T.E., "The Biology of Eelgrass with Special

Reference to Hempstead and South Oyster Bays, Nassau County, Long Island,

New York," Contribution No. 3, Department of Conservation and Waterways,

Hempstead (Long Island), N.Y., 1968.

This report includes a literature review of the history, biology, associated fauna, and nutritive values of eelgrass and techniques for transplanting and harvesting eelgrass in southeastern Nassau County, New York.

17. BURRELL, D.C., and SCHUBEL, J.R., "Seagrass Ecosystem Oceanography,"

Seagrass Ecosystems: A Scientific Perspective, C.P. McRoy and C.

Helfferich, eds., Marcell Dekker, Inc., New York, 1977, pp. 195-232.

This is a review of some aspects of the chemical, geological, and physical

oceanography of sevr ; seagrass systems.

18. CAMP, D.K., COBB, S.P., and VAN BREEDVELD, J.F., "Overgrazing of Seagrasses by a Regular Urchin, Lytechinus variegatus," Bioscience, Vol. 23,

No. 1, Jan. 1973, pp. 37-38.

Destruction of offshore seagrass beds by aggregations of the urchin,

Lytechinus vaviegatus, is described for a large area in Dixie County,

Florida. The seagrasses affected were primarily turtlegrass (Thalassia

testudinum), with lesser amounts of manateegrass (Syringodium filiforme) and

shoalgrass (Diplanthera wrightii). Approximately 20 percent of the area was

damaged by urchin overgrazing. Urchin density averaged 636 individuals per

square meter.

19. CARLTON, J.M., et al., "Techniques for Coastal Restoration and Fishery

Enhancement in Florida," Florida Marine Research Publication No. 15,

Florida Department of Natural Resources Marine Research Laboratory, St.

Petersburg, Fla., Oct. 1975.

Interim guidelines for reestablishment of coastal vegetation are outlined. Several perennial plants including sea oats and bitter panicgrass are

recommended for stabilizing sand dunes; both of these species are currently

11
available from private nurseries. Smooth cordgrasp and black needle rush are

recommended for marsh planting. With appropriate care, such plants can be

removed from natural stands and transplanted to a low-energy coast of gradual

slope. Black, red, and white mangroves are suggested for reestablishing mangrove areas; Loot-balling of 3- to 5-foot-tall trees is a successful procedure. For grass bed restoration, four seagrasses may be used: turtlegrass,

shoalgrass, manateegrass, and widgeongrass. Planting densities, transplanting

times, and procedures for removal and care are discussed for each grass. The

guidelines also describe habitat development using artificial fishing reefs

and oyster reefs. Materials and location should be selected to promote maximum fisheries survival.

20. CARR, W.E.S., and ADAMS, C.A., "Food Habits of Juvenile Marine Fishes

Occupying Seagrass Beds in the Estuarine Zone Near Crystal River,

Florida," Transactions of the American Fish Society, Vol. 102, No. 3, July

1973, pp. 511-540.

A quantitative gravimetric analysis was made on the stomach contents of

juveniles of 21 species of fishes from seagrass beds near Crystal River,

Florida. The analysis was based on dry weights of food items and is expressed

as percent of total stomach contents. An analysis of the stomach contents of

small, sequentially arranged size classes enabled delineation of discrete

ontogenetic changes in food habits in many of the species.

21. CHURCHILL, A.C., COK, A.E., and RINER, M.I., "Stabilization of Subtidal

Sediments by the Transplantation of the Seagrass Zostera marina," Sea

Grant Publication No. 78-15, Marine Science Research Center, State

University of New York, Stony Brook, Dec. 1978.

Zostera marina has been successfully transplanted on dredge spoil, and

appears to stabilize unconsolidated sediments. Researchers recommend manually

transplanting miniplugs of seagrass sediment-free clusters, four to six shoots

together with entangled roots and rhizomes. A total of 5.061 miniplugs were

planted in an 0.06-hectare area with 80 percent survival. A twofold and

threefold increase in rhizome length and shoot number, respectively, was noted

during the first 4 months. The estimated cost of planting 0.41 hectare

(I acre) of seagrass is $3,370.

22. COTTAM, C., and ADDY, C.E., "Present Eelgrass Condition and Problems on

the Atlantic Coast of North America," Transactions of the North American

Wildlife Conference, Vol. 12, 1947, pp. 387-398.

Eelgrass was widespread in the brackish water bays and estuaries along the

Atlantic coast. The plant disappeared in 1931 and 1932, causing great ecological upheaval, but began to recover by 1945 and 1946. Information is tabulated from more than 50 observers of the location and condition of eelgrass

beds in 1946. In favorable areas, eelgrass develops by natural reproduction.

23. COWPER, S.W., "The Drift Algae Community of Seagrass Beds in Redfish Bay,

Texas," Contributions in Marine Science, University of Texas Marine

Science Institute, Austin, Vol. 21, Aug. 1978, pp. 125-132.

Large quantities of drift algae found over seagrass beds in Redfish Bay,

Texas, showed net productivity and competed for light with the seagrasses.

12
The biomass of algae was very small compared to that of the seagrasses; how

ever, the algae served as a resource for animals and reduced light over the

seagrass beds.

24. DOWN, C., and WITHROW, R., "Vegetation and Other Parameters in the Brevard

County Bar-Built Estuaries," Report No. NASA-CR-158242, Report-06-73,

Brevard County Health Department, Titusville, Fla., 1973.

Low-altitude aerial photography, using specific interpretive techniques,

can effectively delineate seagrass beds, oysterbeds, and other underwater

features. Imagery was tested using several data analysis methods, ground

truth, and biological testing. Approximately 45,000 acres of seagrass beds,

2,500 acres of oysterbeds, and 4,200 acres of dredged canals were mapped.

These data represent selected sites only. Areas chosen have the highest

quality water in Brevard County and are among the most highly recognized

biologically productive waters in Florida.

25. DRYSDALE, F.R., and BARBOUR, M.G., "Response of the Marine Angiosperm

Phyllospadix tovreyi to Certain Environmental Variables: A Preliminary

Study," Aquatic Botany, Vol. 1, 1975, pp. 97-106.

Leaf growth of PhylZospadix torreyi was noted both in the field and in

laboratory culture. Field winter growth rate did not appear to depend on

aspect or slope of substrate. In that part of the intertidal zone which

P. toreyi dominates, average dry weight of leaf material was about 300 grams

per square meter. It was hypothesized that the spring growth rate is greater

than the measured winter rate, and that increasing daily incident light energy

triggers the change. In the laboratory cultures, optimum growth occurred in

full strength seawater (29,000 parts per million), under lO0-lumen-per-squarefoot light intensity (12-hour day), and at a water temperature of 120 to 140

Celsius. Growth declined in lower salinities, under lower light intensities,

and at higher temperatures. However, the magnitude of decline indicated that

tolerance ranges of P. toreyi for salinity, light, and temperature are

relatively broad.

26. EARLE, S.A., "Benthic Plants in the Eastern Gulf of Mexico," Proceedings

of Marine Environmental Impliiations of Offshore Drilling in the Eastern

Gulf of Mexico, R.E. Smith, ed., State University System of Florida,

Institute of Oceanography, St. Petersburg, Fla., 1974, pp. 153-156.

Benthic plants in the Gulf of Mexico have considerable influence on shore

primary productivity, due to the broad, shallow Continental Shelf. Seagrasses

and algae are significant biologically by providing a substrate for invertebrates, and geologically by precipitating calcium carbonate from seawater.

There is little information available on the ecology, distribution, and

general biology of benthic plants in the gulf.

27. EDWARDS, P., "Illustrated Guide to the Seaweeds and Seagrasses in the

Vicinity of Port Aransas, Texas," Contributions in Marine Science, University of Texas Marine Science Institute, Austin, Vol. 15 (supp.),

Sept. 1970.

This report provides a key to the identification of species of algae and

seagrasses, including Thalassia, Ruppia, Diplanthera, and Halophila, along the

Texas coast.

13
28. EDWARDS, R.R.C., "Ecology of a Coastal Lagoon Complex in Mexico," Estuarine and Coastal Maine Science, Vol. 6, No. 1, Jan. 1978, pp. 75-92.

Primary production, oxygen consumption of the substrate, and biomass of

invertebrates and fish were measured in a Mexican coastal lagoon. Net production in the water column was sufficient for the metabolic requirements of the

infauna in the wet season; production by macrophytes, e.g., Ruppia ma itima,

covered the increased input necessary for the epifauna and for deposition in

the substrate. Bacterial respiration accounted for an estimated 61 percent,

melobenthos and macrobenthos for 27 percent, and inorganic uptake for 12 percent of substrate respiration on the lagoon flats. Differences in oxygen

uptake by the substrate were related to differences in organic contents.

Practical applications for the lagoon shrimp fishery are discussed.

29. ELEUTERIUS, L.N., "A Study of Plant Establishment on Spoil Areas in

Mississippi Sound and Adjacent Waters," U.S. Army Engineer District,

Mobile, 1974 (unpublished, Contract No. DACWOI-72-C-0001).

Techniques were developed for transplantation of seagrasses and emergent

vascular plants of both marshes and dunes on respective areas of barren sea

bottom and dredge material. Anchors were developed for holding the transplants of three species of seagrass. Halodule beaudettei (shoalgrass) transplants had the greatest survival rate and demonstrated the most rapid rate of

vegetative growth. Unsuccessful transplants were attributed to biological

characteristics of the species, especially related to vegetative morphology,

sediment deposition, and erosion.

Ten marsh and dune species were transplanted to random plots to determine

the best species, season, method, and location for transplanting. Biological

information on the species and ecological information on the dredged-material

disposal areas were obtained. Hypersalinity of soil water of certain spoil

areas was detrimental to transplants. Panicum amarum var. amarulum and

Panicum repens were extremely successful; however, Distichlis spicata, Spartina alterniflora, and Spartina patens demonstrated superior performance under

certain conditions.

30. ELEUTERIUS, L.N. "Submergent Vegetation for Bottom Stabilization," Fstuarine Research, Vol. 2, Academic Press, New York, 1975, pp. 439-456.

Thalassia testudinum, Cymodocea mnnatorum, and Diptanthe7a wrightii were

transplanted from natural stands to barren submerged spoil areas and control

areas adjacent to undisturbed seagrass beds. Anchoring devices were developed

to hold the transplants in place regardless of water depth. Diplanthera

wrightii had the highest survival, and its growth rate exceeded that of

T. testudinum; C. manatorwn did not survive at all. Some characteristics of

the morphology and growth rate of the grasses were compared under varying

conditions of sediment deposition and erosion. In view of its distribution,

growth, tolerance to sediment deposition, D. wrightii is the best candidate

for further transplant studies. Successful transplants were established in

control areas whereas no successful transplants were established on dredged

material. Low temperatures and prolonged exposure to low salinity apparently

affect seagrass beds and transplants adversely. Available plant nutrient

levels of bottom (substrate) samples did not vary appreciably between vegetated and barren areas.

14
31. ELEUTERIUS, L.N., "The Seagrasses of Mississippi," Journal of the Mississipi A*adenr. of Science, Vol., 22, 1977, pp. 57-79.

Biological features of the local species of seagrass, including productivity and decompositional aspects, are reviewed. New information is

presented on the reproductive biology, productivity, culture, and salinity

tolerance with notes on the local distribution of seagrasses. Thalassia

testudinum (turtlegrass) has been studied in more detail than Halodule

beaudettei (shoalgrass), Cymodocea filiformis (manateegrass), or Halophila

engelmanii. Most research on T. testudinum has been on morphology, productivity, and decomposition. Major factors affecting the distribution are also

explored.

32. ELEUTERIUS, L.N., and MILLER, G.J., "Observations on Seagrasses and

Seaweeds in Mississippi Sound Since Hurricane Camille," Journal of the

Mississippi Academy of Science, Vol. 21, 1976, pp. 58-63.

33. FERNALD, M.L., and WIEGAND, K.M., "The Genus Ruppia in Eastern North

America," Rhodora, Vol. 16, No. 187, July 1914, pp. 119-127.

This study shows that in North America there are several clearly definable

variants or a combination of variable characteristics in Ruppia mrritima.

Whether these should be regarded as different species is questionable.

34. FRY, B., and PARKER, P.L., "Animal Diet in Texas Seagrass Meadows: 6 13C

Evidence for the Importance of Benthic Plants," Estuarine and Coastal

Aarine Science, Vol. 8, No. 6, June 1979, pp. 499-509.

More than 340 animals from Texas estuarine and offshore seagrass beds were

analyzed for their stable carbon isotope ratios ( 13C values). Fish and

shrimp from seagrass beds had significantly more 13C by an average of 3.3 to

5.1 parts per thousand than comparable animals collected offshore. One polychaete worm species, Diopatra cuprea, collected in seagrass meadows were as

much as 8.3 parts per thousand enriched in 13C compared to specimens from

areas where phytoplankton were the major primary producers. The differences

in 6

13

C values are attributed to differences in diet. The data support the

hypothesis that seagrasses and other benthic plants in Texas bays are significant sources of nutrition for juvenile shrimp and fish.

35. FRY, B., SCALAN, R.S., and PARKER, P.L., "Stable Carbon Isotope Evidence

for Two Sources of Organic Matter in Coastal Sediments: Seagrasses and

Plankton," Geochimica et Cosmochimica Acta, Vol. 41, Pergamon Press, Inc.,

New York, 1977, pp. 1875-1877.

Organic carbon from sediments collected in Texas seagrass meadows was rich

in a stable isotope of carbon (13C) by an average of 6.6 parts per thousand

relative to organic carbon from offshore sediments. Within the south Texas

bay system, delta 13 C values became increasingly more typical of offshore

sediments with increasing distance from seagrass meadows. This permits the

use of carbon isotope data as a measure of the relative contributions of seagrasses and plankton to sedimentary organic matter.

36. FUSS, C.M., and KELLY, J.A., "Survival and Growth of Seagrasses Transplanted Under Artificial Conditions, Bulletin of Marine Science, Vol. 19,

No. 2, Apr. 1969, pp. 351-365.

Survival and growth of turtlegrass (Thalassia testudinum) and shoalgrass

(Diplanthera waightii) transplanted in aquariums and through-flow seawater

15
tanks were measured. In aquariums, turtlegrass survived 7 months and shoalgrass 3.5 months. In tanks, turtlegrass lived 12 months and produced new

leaves, roots, and rhizomes, but only a few shoalgrass plants survived.

37. GOERING, J.J., and PARKER, P.L., "Nitrogen Fixation by Epiphytes on Seagrasses," Limnotogy and Oceanography, Vol. 17, No. 2, Mar. 1972,

pp. 320-323.

Seagrasses (Thatassia testudinum, Cymodocea manatorum, Diplanthera

wrightii, and Ruppia na'itima) in Redfish Bay, Texas, showed nitrogen-fixing

activity as measured by the acetylene reduction technique. Evidence is presented that epiphytes and not the macrophytes are responsible for the observed

fixation, which suggests nitrogen-fixing epiphytes play an important role in

the nitrogen economy of seagrass communities.

38. GOOD, R.E., et al., "Analysis and Delineation of the Submerged Vegetation

of Coastal New Jersey: A Case Study of Little Egg Harbor," Rutgers State

University, New Brunswick, N.J., Jan. 1978.

The submerged vegetation in Little Egg Harbor estuary of New Jersey was investigated, from September 1977 to January 1978, to determine the identification and the delineation of submerged vegetation. Remote sensing was used

to delimit the important submerged macrophytes. The functions these species

play in the estuarine ecosystem were also described.

Field sampling revealed extensive beds of eelgrass (Zostera mrina) and

lesser amounts of widgeongrass (Ruppia maritima); however, significant amounts

of algal species important in other New Jersey coastal bays (sea lettuce, Ulva

lactuca; spaghetti grass, Codium fragite; and a red alga, Grvacilaria) were absent. This study demonstrated that the distribution of submerged vegetation

in Little Egg Harbor can be determined through remote sensing.

A survey of literature revealed that the major functions of eelgrass beds

include (a) a role in grazing and detrital food chains, (b) creation of habitat for epiphytes, epifauna, finfish, and shellfish, (c) participation in

nutrient cycles, and (d) stabilization of sediments. Eelgrass beds are viewed

as an important contributor to the normal functioning and health of estuarine

ecosystems.

39. HANLON, R., and VOSS, G., "A Guide to the Seagrasses of Florida, the Gulf

of Mexico, and the Caribbean Region," University of Miami, Sea Grant Field

Guide Series No. 4, July 1975.

More species of marine flowering plants are found in the Gulf of Mexico

and Caribbean Sea than anywhere else in the Western Hemisphere. They include

the turtlegrass (Thalassia testudinum), shoalgrass (Halodute wvightii), manateegrass (Syvingodium fiZiforme), widgeongrass (Ruppia maritinm), Hatophila

baillonis, and HaZophila engelmanni. A seventh species, eelgrass (Zoetera

marina), is included in order to distinguish it from the native species; however, it is a temperate species occurring as far south as North Carolina with

only a few records of occurrence in Florida. Eelgrass should not be confused

with turtlegrass or shoalgrass, and the distinguishing characters of each are

given.

16
40. HARRISON, P.G., "Decomposition of Macrophyte Detritus in Seawater:

Effects of Grazing by Amphipods," Oikos, Vol. 28, No. 23, Copenhagen,

Denmark, 1977, pp. 165-169.

In the laboratory, amphipods collected from detritus in shallow water

grazed on eelgrass (Zostera marina) but did not consume leaves from which the

epibionts had been removed. The action of two adult amphipods increased the

rate of decomposition of Z. marina leaf particles by 32 percent (50 Celsius)

and 35 percent (210 Celsius) in 24 days. Experiments with homogeneously

14C-labeled hay as the source of detritus gave similar results. The addition

of inorganic nitrogen and phosphorus also increased the rate of decomposition,

but the maximum daily rate was only 1.16 percent and was attained after 28

days.

41. HARRISON, P.G., and MANN, K.H., "Chemical Changes During the Seasonal

Cycle of Growth and Decay in Eelgrass (Zostera ma rina) on the Atlantic

Coast of Canada," Journal of the Psheries Reseach Board of Canada, Vol.

32, No. 5, May 1975, pp. 615-621.

Newly formed leaves of eelgrass in winter and spring contained maximum

levels of total organic matter (90 percent of dry weight), soluble organic

fraction (45 percent), carbon (42 percent), and nitrogen (4.8 percent). These

decreased as the leaves matured, aged, and died. Soon after death, the leaf

contained only 70-percent total organic matter, 28-percent soluble organic

matter, 30-percent carbon, and 1.5-percent nitrogen. Intact dead leaves

showed little further change. The crude protein determination overestimated

true protein up to 180 percent. The carbon-to-nitrogen ratio (C:N) was an

unreliable index of the nutritional value of the plant. The two growth forms

were probably in response to wave action and substrate composition. Day

length, not temperature, probably controls the seasonal growth cycle.

42. HARRISON, P.G., and MANN, K.H., "Detritus Formation from Eelgrass (Zostera

marina L.): The Relative Effects of Fragmentation, teaching, and Decay,"

Limnoloqy and Oceanography, Vol. 20, No. 6, Nov. 1975, pp. 924-934.

In the laboratory, dead eelgrass leaves lost a maximum of 35 percent of

the original (dry) weight in 100 days at 20° Celsius. Whole leaves lost 0.5

percent of their organic content per day whereas particles smaller than

1 millimeter lost I percent per day. Sterilization of leaves by dry heat or

potassium cyanide showed that leaching accounted for 82 percent of the total

loss of organic matter from predried material and 65 percent of the loss from

undried material. Bacteria alone increased the nitrogen content of the detritus but only slowly degraded the leaf material. When protozoa were introduced, they grazed on the bacteria, maintained the bacterial population in an

active metabolic state, and hastened the rate of decay. The C:N ratio of

incubated detritus decreased from more than 20:1 to as low as 11:1, indicating

an increase in its potential food value.

43. HARTOG, C.D., "A Key to the Species of Halophila (Hydrocaritaceae), with

Descriptions of the American Species," ACTA Botania Neevrtandica, Vol. 8,

Amsterdam, The Netherlands, 1959, pp. 484-489.

44. HARTOG, C.D., Seagvasses of the World, North Holland Publishing Co.,

Amsterdam, The Netherlands, 1970.

A description and species key is given for the genera Zostera, Phyllospadix, Heterozostera, Posidonia, Halodule, Cymodocea, Syringodium, Thalassodendron, Amphilobolis, Enhalus, Thalassia, and Halophila. The origin,

17
evolution, and geographical distribution of seagrasses are also discussed, and

a key to the identification of sterile specimens is included.

45. HARTOG, C.D., "Structure, Function, and Classification in Seagrass Communities," Seagrass Ecosystem: A Scientific Perspective, C.P. McRoy and

C. Helfferich, eds., Marcel Dekker, Inc., New York, 1977, pp. 89-121.

The seagrasses are divided into six growth forms. These growth forms are

linked to differences in ecology. It is suggested that the ability of the

plant to compete is linked to growth form. The complexity and functions of

community structures of seagrasses are described.

46. HECK, K.L., Jr., "Comparative Species Richness, Composition, and Abundance

of Invertebrates in Caribbean Seagrass (Thalassia testudinum) Meadows

(Panama)," Marine Biology, Vol. 41, No. 4, 1977, pp. 335-348.

This article reports on a year-long study of epibenthic invertebrates from

seagrass (Thalassia testudinum) meadows along the Caribbean coast of Panama

and the Panama Canal Zone. Differences in species composition and abundance

among sites were primarily due to the proximity of surrounding habitats. Coral

reefs contained many species that utilize the seagrass meadows. Important seasonal fluctuations in both species number and abundance occurred at each of

the sites. Several species of decapod crustaceans bred year round although

seasonal differences occurred in the percentage of oviparous females. Overall

species composition was similar to that reported in tropical and subtropical

seagrass meadows elsewhere.

47. HILLSON, C.J., Seaweeds: A Color-Coded, Illustrated Guide to Common

Marine Plants of the Fast Coast of the United States, Keystone Books, Pennsylvania State University Press, University Park, Pa., 1977.

This is a color-coded guide to the identification of marine plants, including turtlegrass (Thalassia teetudinum) and eelgrass (Zostera marina),

commonly found on the east coast of the United States. A glossary and a bibliography are also included.

48. HIRTH, H.F., KLIKOFF, L.G., and HARPER, K.T., "Sea Grasses at Khor Umaira,

People's Democratic Republic of Yemen, with Reference to their Role in the

Diet of the Green Turtle, Chelonia ?mdas," Fisheries Bulletin, Vol. 71,

No. 4, Department of Commerce, National Marine Fisheries Service, Oct.

1973, pp. 1093-1097.

Studies were made on the seagrass pastures at Khor Umaira, the People's

Democratic Republic of Yemen, in July 1972. The standing crop in an equally

mixed pasture of Cymodocea serrulata and Syringodium isoetifolium was greater

than in a pure stand of C. serrulata. The average caloric content of the

leaves of five genera of seagrasses at Khor Umaira ranged between 4.54 and

4.66 kilocalories per gram dry weight, ash-free. These values are similar to

the values reported for seagrasses in the South Pacific and in the Caribbean. The results show that the number of calories in the standing crop can

be calculated from estimation of percent cover. The role of seagrasses in the

management schemes of the green turtle (Chelonia mydas) is described.

49. HOTCHKISS, N., Common Marsh, Underwater and Floating-Leaved Plants of the

United States and Canada, Dover Publications, Inc., New York, 1972.

This is a reprint of two circulars on field identification of marsh and

water plants in North America. It describes all of the wild-flowering plants,

ferns, liverworts, and Characeae which have underwater or floating-leaved

18
forms and, at the same time, have characteristics by which a person can tell

them apart with the naked eye. Group descriptions are given for the different

kinds that cannot be told apart without a hand lens or microscope or are without flowers or seeds.

50. HUMM, H.J., "Seagrasses on the Northern Gulf Coast," Bulletin of Marine

Science, Vol. 6, No. 4, Dec. 1956, pp. 305-308.

Observations in Mississippi Sound indicate that at least five species of

marine monocotyledonous plants occur in abundance along the northern gulf

coast and may be virtually continuous between Florida and Aransas, Texas. An

annotated list of species and a key are included.

51. HUHIM, H.J., "Epiphytes of the Seagrass, Thalassia testudinum, in Florida,"

Bulletin of Marine Science, Vol. 14, No. 2, June 1964, pp. 306-341.

A total of 113 species of algae are reported occurring as epiphytes on the

seagrass, Thalassia testudinwn, 92 of which have been recorded from the south

Florida area, 20 to 25 percent of the total algal flora. Two groups of epiphytes are recognized, the year-round species and the seasonal annuals. Among

the year-round species are calcarcous Corallinaceae which contribute significantly to the sediments of seagrass beds; the seasonal annuals are a group of

large plants which may become sufficiently abundant during winter and spring

to shade the T. testudinum significantly. Each species is annotated, and a

key to the species known to occur as epiphytes on T. testudinum in south

Florida is provided. Stictyosiphon ssp. and Polysiphonia harveyi are newly

reported for Florida; Griffithsia barbata is newly reported for the Bahamas.

52. HUMM, H.J., "Seagrasses," Proceedings of Marine Environmental Implications

of Offshore Drilling in the Eastern Gulf of Mexico, R.E. Smith, ed., State

University System of Florida, Institute of Oceanography, St. Petersburg,

Fla., Mar. 1974, pp. 149-151.

Florida's gulf coast has seagrass beds that extend 10 miles or more out on

the gently sloping Continental Shelf. Three species (Thalassia testudinum,

Syringodium filiforme, and Halodule wrightii) make up 99 percent of the biomass of these beds. Three other species occur but in smaller quantity or a

more limited distribution. Seagrasses are important primary producers,

exceeding the productivity of phytoplankton in the areas they occupy, and they

also provide an essential environment for many species of invertebrates and

fishes.

53. JAGELS, R., "Studies of a Marine Grass, Thalassia testudinum I., Ultrastructure of the Osmoregulatory Leaf Cells," American Journal of Botony,

Vol. 60, No. 10, Oct. 1973, pp. 1003-1009.

Turtlegrass (Thalassia testudinum) grows completely submerged and differs

from intertidal and other halophytic angiosperms in that it has no specialized

salt-secretory glands. Osmoregulation appears to be by the epidermal -leaf

cells. The ultrastructure and proposed mode of secretion are similar to that

of the salt marsh monocot, Spartina, but differ from that found in dicots.

19
54. JONES, C.R., and SCHUBEL, J.R., "Distribution of Surficial Sediments and

Eelgrass in New York's South Shore Bays: An Assessment from the

Literature," Special Report No. 13, Reference 78-1, Marine Sciences

Research Center, State University of New York, Stony Brook, 1978.

This report covers all published and unpublished information available on

the distributions of surficial sediments and eelgrass (Zostera marina) in New

York's south shore bays. Graphical and tabular summaries of sediment texture

and eelgrass cover are presented.

55. KELLER, M., and HARRIS, S.W., "The Growth of Eelgrass in Relation to Tidal

Depth," Jour'nal of Wildlife Management, Vol. 30, No. 2, 1966, pp 280-285.

The growth of eelgrass (Zostera mrtzina) in relation to tidal depth was

studied at three areas of Humboldt Bay, California. Six contours of bay

bottom between +1.0 and -1.5 feet in relation to mean lower low water (MLLW)

datum were sampled. The upper limit of eelgrass growth was at or slightly

above +1.0 foot. This isobath was exposed to air about 15 percent of the

time. The percent of eelgrass coverage, mean turion length, and eelgrass biomass all increased with increases in water depth. The density per square foot

and the number of leaves per turion did not vary with depth. The optimum

depth for eelgrass production was about -1.0 foot. More than 90 percent of

the biomass and about 60 to 70 percent of the eelgrass acreage in south

Humboldt Bay occur at or below MLLW.

56. KELLY, J.A., Jr., FUSS, C.M., and HALL, J.R., "The Transplanting and Survival of Turtle Grass, Thalassia testudinuw, in Boca Ciega Bay, Florida,"

Fishery Bulletin, Vol. 69, No. 2, Apr. 1971, pp. 273-280.

Turtlegrass was transplanted to an unvegetated, dredged canal and a handcleared part of a flourishing grass bed. Complete or partial success was

attained in 7 of 14 planting methods used. The best method, in which short

shoots (rhizomes removed) were dipped in a solution of plant hormone (naphthalene acetic acid) and attached to construction rods for transplanting, was

100 percent successful and may be suitable for general application.

57. KENWORTHY, W.J., and FONSECA, M., "Reciprocal Transplant of the Seagrass

Zostera marina L. Effect of Substrate on Growth," Aquaculture, Vol. 12,

No. 3, Nov. 1977, pp. 197-213.

Eelgrass (Zoste'a marina) is an important component of the temperate

coastal ecosystem. The effect of different substrate types on Z. marina

growth was studied using transplants of individual shoots and rhizomes. The

new leaves formed the most reliable parameter for relative production. Transplants originating from a natural silt environment displayed best overall

growth. Plants grown in a silt substrate continually afforded better growth.

The quality of the sediment was also examined. Plants grown in undisturbed

natural sediments were more successful than plants in sediments which were

disturbed. Aspects of the physiology and ecology of Z. marina are discussed

with reference to the substrate.

58. KOCH, S.J., ELIAS, R.W., and SMITH, B.N., "Influence of Light Intensity

and Nutrients on Laboratory Culture of Seagrasses," Contributions in

Marine Science, University of Texas Marine Science Institute, Austin, Vol.

18, Sept. 1974, pp. 221-227.

qalodutle wrightii, FlatophiZa engemanii, Ruppia ireitima, Syring dium

filiforme, and Thalassia testudinum were cultured in filtered seawater

20
converted to Von Stosch algal culture medium. The culture technique eliminated much of the loss due to dieback of leaf tissue and made possible increases in fresh weight of 3 to 30 percent in a 4-week period for the five

species. Optimal growth for all species was observed at light intensities of

200 to 450 foot-candles. By contrast, growth was much slower at light intensities of less than 200 and greater than 450 foot-candles.

59. LOT, A., "General Status of Research on Seagrass Ecosystems in Mexico,"

Seagrae Ecosystems: A Scientific Perspective, C.P. McRoy and

C. Helfferich, eds., Marcel Dekker, Inc., New York, 1977, pp. 233-245.

This is a discussion on the reasons for the sparse data on Mexico's coast,

the different coastal seagrasses (Thalassia, Zostera, Hatophila, Halodule,

Syringodium) found in the area, and the state of seagrass ecosystems research,

especially in Veracruz, Mexico. Also included is an assessment of the effects

of human activity on seagrass ecosystems, and suggestions of priority areas in

Mexico for future seagrass research.

60. MANN, K.H., "Ecological Energetics of the Seaweed Zone in the Marine Bay

on the Atlantic Coast of Canada, Part I. Zonation and Biomass of Seaweeds," Ma.ine Biology, Vol. 12, No. 1, 1972, pp. 1-10.

A survey of the zonation of seaweed in St. Margaret's Bay, Nova Scotia,

Canada, showed eight major zones: (1) Fucus and Ascophyltum, (2) Cho'da with

filamentous browns, (3) Chondrus criepus, (4) Zostera marina, (5) Laminaia

digitata with L. longicruris, (6) Laminaria longicruris, (7) L. longicu.is

with Agartm cribroezn, and (8) Agarmw cribroeum with Ptilota eerata. Zoetera

mar*ina occurred at the same level as C. ciespue but replaced it in sheltered

water.

61. MARINE EDUCATION CENTER, "The Seagrasses and Marine Algae of Mississippi

Sound," Marine Educational Leaflet No. 7, Marine Educational Center, Gulf

Coast Research Laboratory, Biloxi, Miss., Nov. 1976.

This leaflet includes a general discussion and listing of the seagrasses

and marine algae in Mississippi Sound.

62. MARSH, G.A., "The Zostera Epifaunal Community in the York River,

Virginia," (whesapeake Science, Vol. 14, No. 2, June 1973, pp. 87-91.

The invertebrates on Zoetera miv'na in the lower York River, Virginia,

were sampled for 14 consecutive months at three different water depths within

a single bed. The five most abundant noncolonial species (Bittium vlkiwn,

Pa acerceis caudata, (repiduta convexa, Ampithoe tongimana, and Fricheonella

attenuat42) accounted for approximately 59 percent of the total fauna. These

species dominated the epifauna. Several other species, including Batanue

impovisue, kfolqula rvnhatteneis, Pot ydora ligni, and F.*colania fuecata, were

abundant for only brief periods. An average index of affinity (58 percent)

between all synchronous sample pairs indicated a generally homogeneous fauna,

although several species were differentially distributed with depth. Exfoliatton of 7. ,rtina after June caused a decline in plant biomass, but the abundance of epifauna continued to increase in the summer and fall. Lowest total

numbers and species counts occurred in February and early March. Diversity

value (H') ranged from 1.92 to 3.90 bits per individual and averaged 3.04

21
bits per individual for all stations. High species numbers in summer were

generally counteracted by relatively low equitabilities (E), with H' showing little seasonal change. The primary sources of nutrition for the epifauna

appeared to be (1) plankton and suspended particulate matter, (2) detritus and

microorganisms on the plant blades, and (3) epiphytic algae.

63. MARSH, G.A., "Ecology of the Gastropod Epifauna of Eelgrass in a Virginia

Estuary," Chesapeake S5cience, Vol. 17, No. 3, Sept. 1976, pp. 182-187.

Twenty-three species of gastropod mollusks, including 10 prosobranchia and

13 opisthobranchia, were collected during a 14-month period from Zostera in

the lower York River, Virginia. During the period, salinities ranged from

16.0 to 22.4 parts per thousand, and temperatures ranged from 2.80 to 28.30

Celsius. Seasonal abundance, depth distribution, and notes on the life cycles

and general ecology of this epifauna are reported. Diastoma va'ium and C'epidula convexa, the two most abundant species collected, occurred throughout

the year.

64. MARSHALL, N., and LUKES, K., "Preliminary Observations on the Properties

of Bottom Sediments With and Without Eelgrass, Zostera marina, Cover,"

Proceedings of the 1969 Nationai Shellfisheries Association, Vol. 60, June

1970, pp. 107-111.

In mid-July sediment conditions in a bed of Zostera marina were compared

with those of an open area on a shoal estuarine site in southern New England.

Zostera marina was rooted out of a plot, the blades were broken off to clear

another tract, and in the open area some of the sediment was raked. Sediments

from the altered and control plots were compared again in mid-August. Organic

carbon, percent water and gross color characteristics for successive levels

through the top 13 centimeters of the sediments were analyzed. Silt-clay was

measured at the sediment surface areas where Z. marina had higher levels of

organic carbon, a higher silt-clay content, and more interstitial water than

did the open areas. Sediments from contrasting areas were more alike beneath

the surface. Possible interrelationships between these surface parameters are

discussed. No changes attributed to the clearing or raking of plots were

observed in the 1-month period.

65. MARYLAND DEPARTMENT OF NATURAL RESOURCES, "Experimental Planting of Bay

Grasses," Pamphlet, Maryland Bay Grasses Oversight Committee, in Cooperation with the Maryland Department of Natural Resources, Annapolis, Md.,

1978.

This pamphlet is for the citizens who wish to plant submerged grasses. It

tells what, where, and how to plant in the Chesapeake Bay. A form for evaluating experimental bay grass transplanting is presented, and it is suggested

that this form be used for evaluating private plantings to provide information

to the Maryland Department of Natural Resources.

66. MAYER, F.L., and LOW, J.B., "The Effect of Salinity on Widgeongrass,

Ruppia maritima," Journal of Witdlife Management, Vol. 34, No. 3, July

1970, pp. 658-661.

The effects of salinity on widgeongrass (Ruppia maritima) were studied in

a greenhouse. Plant reproduction and seed germination were greatest in freshwater. Plants grown in salinities up to 12,000 parts per million produced

22
seeds; few seeds were produced at the highest salinities. Six-week-old plants

could tolerate a salinity of 27,000 parts per million; older plants could not

tolerate salinities above 21,000 parts per million.

67. McMAHAN, C.A., "Biomass and Salinity Tolerance of Shoalgrass and Manateegrass in Lower Laguna Madre, Texas," Journal of Wildlife Management, Vol.

32, No. 3, July 1968, pp. 501-506.

Three different shoalgrass (Diplanthera wrightii) stands and a manateegrass (Syringodium filifone) community in lower Laguna Madre, Texas, were

sampled for biomass. The standing crop of wet shoalgrass herbage and roots is

estimated to be 4,656 pounds per acre. The standing crop of wet manateegrass is estimated to be 5,795 pounds per acre. Shoalgrass exhibits a seasonal abundance; manateegrass is not seasonal. Shoalgrass sprigs planted in

culture vessels lived in salinities ranging from 9.0 to 52.5 parts per thousand, but died in salinities of 3.5 and 70.0 parts per thousand. Manateegrass rhizomes planted in culture vessels survived best in a salinity of 35.0

parts per thousand; those planted in a vessel containing 52.5 parts per thousand died. Shoalgrass is important to waterfowl and provides spawning and

nursery grounds for fish and shrimp. Manateegrass appears to be of minimal

value.

68. McMILLAN, C., "Experimental Studies on Flowering and Reproduction in

Seagrasses," Aquatic Botany, Vol. 2, No. 2, June 1976, pp. 87-92.

Flowering and reproduction of seagrasses in laboratory cultures were compared with responses of the same clones in Redfish Bay, Texas. Under controlled conditions, Halophila engelmanni produced flowers continuously from

January to September. Flower production in the bay was confined to the period

from April to mid-June. The effects of salinity, temperature, and photoperiod were studied in the laboratory and monitored in the bay. Of these,

temperature seemed to be the chief control of the flowering period of

H. engelmanni. Under laboratory conditions, no flowering was recorded in

Thalassia testudinum, Syringodium filiforme, Ruppia maritia, or Halodule

wrightii, but the flowering of H. wrightii in the bay from May to August suggested a response to higher temperatures than indicated for H. engelmanni.

Fruit development of H. wrightii in the laboratory also indicated a higher

temperature response.

69. McROY, C.P., "The Distribution and Biogeography of Zostera marina, Eelgrass in Alaska," Pacific Science, Vol. 22, 1968, pp. 507-513.

Zostera marina (eelgrass) is common on the Alaska coast, from the lagoons

on the north coast of the Seward Peninsula to the southern limit of Alaska and

beyond. New records of Z. marina in Alaska are from Adak and Atka in the

Aleutian Islands, Chagvan and Nanvak Bays and Nunivak Island, and Lopp and

Ikpek lagoons on the Seward Peninsula. In Prince William Sound, the distribution of Z. marina was altered by an uplift associated with the March 1964

earthquake.

70. McROY, C.P., "Eelgrass Under Arctic Winter Ice," Nature, Vol. 224, No.

5221, Nov. 1969, pp. 818-819.

Eelgrass was found living under the winter sea ice in Safety Lagoon, an

embayment of the Bering Sea near Nome, Alaska. A submarine television system

revealed that the plants were in good vegetative condition, and in 20 to 30

23
centimeters of water between the sediment and the undersurface of the ice.

The odor of hydrogen sulphide, and subsequent tests with an oxygen probe,

showed this water to be anoxic.

71. McROY, C.P., "Standing Stocks and Other Features of Eelgrass, Zostera

marina, Populations on the Coast of Alaska," Journal of the Fisheries

Research Board of Canada, Vol. 27, No. 10, Oct. 1970,.pp. 1811-1821.

Eelgrass populations were sampled from southeast Alaska to Bering Strait.

Those in Kinzarof and Izembek lagoons on the Alaska Peninsula had the highest

standing stocks (mean, 1,510 grams dry weight per square meter); populations

in Calder Bay in southeast Alaska had the lowest (65 grams dry weight per

square meter). Caloric content of eelgrass averaged 4,211 calories per gram

in the leaves and 3,571 calories per gram in the roots and rhizomes. The concentration of chlorophyll a in eelgrass had a mean of 0.513 milligram per

gram fresh weight with one exception. Population densities were high in

Kinzarof and Izembek lagoons (mean, 4,576 turions per square meter) and low in

other sample areas (599 turions per square meter). Flowering plants made up 3

to 4 percent of the total population. Mean leaf length varied from 13 to 48

centimeters and width from 2.4 to 5.1 millimeters. The differences in the

eelgrass populations appeared to be related to local conditions rather than a

large geographical gradient.

72. McROY, C.P., and GOERING, J.J., "Nutrient Transfer Between the Seagrass

Zostera marina and its Epiphytes," Nature, Vol. 248, No. 5444, Mar. 1974,

pp. 173-174.

The production of leaf epiphytes on Zostera marina may be indirectly sustained by nutrients in the sediments. The transfer of nitrogen and carbon was

measured using laboratory techniques and controls. Results indicate a direct

transfer of carbon and nitrogen from Z. marina to its epiphytes on the leaves,

showing a symbolic relationship. Nutrients are likely absorbed by the rootrhizome system from the soil and distributed to all parts of the plant.

Epiphytes probably absorb nutrients that are leached through leaves.

73. McROY, C.P., and HELFFERICH, C., eds., Seagrasses Ecosystems: A Scientific

Perspective, Vol. 4, Marcel Dekker, Inc., New York, 1979.

The report provides recommendations for research and includes background

notes. These constitute a framework for an interdisciplinary study on

seagrass ecosystems. Subject areas considered were productivity-physiology,

systematic ecology, decomposition, consumer ecology, and oceanography. It was

the opinion of these scientists that the significance of the overall contribution of seagrass ecosystems to the ecology of the ocean cannot be adequately

evaluated on the basis of available knowledge. The evidence emphasizes the

need to document and understand the role of seagrass ecosystems before the

pressures of an overpopulated world's technological expansion unwittingly

destroy the seagrass meadows.

74. McROY, C.P., and PHILLIPS, R.C., "Supplementary Bibliography on Eelgrass,

Zostera marina," Special Scientific Report, U.S. Fish and Wildlife

Service, Washington, D.C., No. 114, Jan. 1968.

This bibliography lists 204 references on eelgrass to supplement an

earlier list issued in 1964 (see Phillips, 1964).

24
75. McROY, C.P., BARSDATE, R.J., and NEBERT, M., "Phosphorus Cycling in an

Eelgrass (Zostera marina L.) Ecosystem," Limnotogy and Oceanography,

Vol. 17, No. 1, Jan. 1972, pp. 58-67.

Uptake and excretion of phosphorus by roots and leaves of eelgrass

(Zostera marina) were dependent on the orthophosphate concentration of the

medium. In a tidal pool dominated by eelgrass, the interstitial reactive

phosphorus concentrations of the sediments were as high as 75 microgram atoms

per liter. The plants absorbed 166 milligrams of phosphorus per square meter

per day and excreted 62 milligrams of phosphorus, per square meter per day

into the water. An amount equivalent to about 41 percent of the reactive

phosphorus excreted, or 3 metric tons of phosphorus, per day was exported from

the lagoon into the Bering Sea. These results open a new pathway to the phosphorus cycle for some estuaries.

76. McROY, C.P., GOERING, J.J., and CHANEY, B., "Nitrogen Fixation Associated

with Seagrasses," Limnology and Oceanography, Vol. 18 No. 6, Nov. 1973,

pp. 998-1002.

The nitrogen fixing of three species of seagrasses, Thalassia testudinum

and Syringodiwn filiforme from Florida and Zostera marina from North Carolina

and Alaska, was examined using the acetylene reduction technique. Rates of

nitrogen fixation were extremely low or undetectable. The results do not

support the generalization of others that this process supplies the nitrogen

required for the high productivity of seagrasses.

77. McROY, C.P., et al., "Survey of Macrophyte Resources in the Coastal Waters

of Alaska," Report No. R-71-6, University of Alaska, Institute of Marine

Science, College, Alaska, May 1971.

This study provides (a) a quantitative assessment of natural stocks of

marine macrophytes (seaweeds and seagrasses) in the coastal water of Alaska,

(b) an evaluation of the commercial value of macrophytes from data on

abundance and chemical composition, (c) a reference herbarium of marine macrophytes, and (d) a compilation of data from literature on the chemical composition of Alaska marine macrophytes. The effort during the first year of study was directed toward the development of quantitative survey techniques. The

significance of the research is to provide the background for the development

of a new industry in Alaska.

78. MENZIES, R.J., ZANEVELD, J.S., and FRATT, R.M., "Transported Turtle Grass

as a Source of Organic Enrichment of Abyssal Sediments Off North

Carolina," Deep Sea Research, Vol. 14, Pergamon Press, Ltd., Great

Britain, Feb. 1967, pp. 111-112.

The finding of a considerable amount of turtlegrass at abyssal depths off

North Carolina and at bathal depth off Florida suggests seagrass as a source

of organic nourishment for the deep-sea floor. Turtlegrass does not grow in

the Carolinas but is abundant in southern Florida, Bermuda, and the Bahamas,

which indicates that the grass is distributed by the Gulf Stream rather than

simple offshore transport.

79. MEYERS, S.P., et al., "Thalassiomycetes VII. Observations on Fungal

Infestations of Turtle Grass, Thalassia testudinum Konig., " Bulletin of

Afarine Science, Vol. 15, No. 3, Sept. 1965, pp. 548-564.

Seasonal studies of fungal infestation of turtlegrass (ThaZassia testudinum) in Biscayne Bay, Florida, revealed a wide range of follicolous fungi

25
regularly associated with this marine phanerogamic plant. The fungi can be

separated into three groups, based on relative abundance and frequency of

isolation. The dominant group includes species of Labyrinthula, the

ascomycete Lindra thalassiae, and the deuteromycetes Hormodendron Cephalosporium, and Dendryphiella arenaria. Variabilities of infestation and differences observed between the foliicolous and lignicolous mycota of estuarine

environments are discussed.

80. MONTGOMERY, J.R., et al., "Release of Cadmium, Copper, Nickel and Zinc by

Sewage Sludge and the Subsequent Uptake by Members of a Turtle Grass

(Thalassia testudinum) Ecosystem," Report No. CEER-2, Energy Research and

Development Administration, Oak Ridge, Tenn., May 1977.

The rates of uptake by a turtlegrass (Thalassia testudinum) ecosystem of

cadmium, chromium, copper, nickel, lead and zinc, which were leached from

sewage sludge by seawater, were determined. The experimental design used

aerated-flowing seawater which passes over a bed of sewage sludge before

traversing a model ecosystem.

81. MORRILL, J.B., "The Submerged and Shoreline Vegetation of Three Canal

Systems, Siesta Key, Florida--Preliminary Observations and Recommendations," Proceedings of the First Annual Conference on Restoration of

Coastal Vegetation in Florida, Hillsborough Community College Environmental Study Center, Tampa, Fla., May 1974, p. 39.

Distribution of marine grasses, water circulation, and water quality were

studied in three canal systems in 1972. Two canal systems had vegetated

shorelines, the other had seawalls. The water quality was different in each

of the three canal systems. Distribution of marine grasses was related to

recruitment, depth and width of the canals, tidal current velocities, and

presence of shoreline vegetation. Recommendations include a canal design for

optimal tidal flushing, trimming of shoreline vegetation, removal of aquatic

plants and debris that enter the open bays, and aeration of the bottom waters

in dead-end canals.

82. NELSON, W.G., "Experimental Studies of Selective Predation on Amphipod:

Consequences for Amphipod Distribution and Abundance," Journal of Experimental Marine Biology and Ecology, Vol. 38, No. 3, May 1979, pp. 225-245.

The relationship between the amphipods found associated with eelgrass

(Zostera marina) and the common predators have been examined by laboratory

experiments and field sampling. Laboratory experiments showed that of the

most abundant potential predators on eelgrass amphipods, the pinfish (Lagodon

rhomboides) and the grass shrimp (Palaemonetes vulgaris) were among the most

effective predators. Selective feeding by these two species, with respect to

prey species, size, and sex, was demonstrated. An examination of the field

data in the light of the laboratory selection experiments suggests that the

presence of pinfish may (a) determine the relative abundances of different

types of amphipod species, (b) determine seasonal changes in species diversity

by selectively removing certain species, and (c) determine, through an interaction with habitat complexity, the spatial distribution of amphipod abundance

and diversity within eelgrass beds.

26
83. NELSON, W.G., "A Comparative Study of Amphipods in Seagrasses from Florida

to Nova Scotia," Pulletin of marine Science, Vol. 30, No. 1, Jan. 1980,

pp. 80-89.

Amphipods associated with seagrass beds were studied along a latitudinal

range from Florida to Nova Scotia. Samples were divided into the Acadian,

Virginian, and Caribbean faunal provinces and compared with respect to mean

density, number of species, diversity, and evenness of amphipods. No significant differences in these parameters among the faunal provinces were found.

For samples from Zostera marina sites, density of amphipods decreased with

increasing latitude. Samples from Thalassia testudinum sites had significantly lower values of density, number of species, and evenness than either

Halodule wrightii or Z. marina sites. Significant differences were found

between the most northern sites and the most southern sites in the size and

relative abundance of epifaunal species (but not infaunal species). These

differences may be due to a difference in predation intensity at the two

locations.

84. ODUM, H.T., "Productivity Measurements in Texas Turtle Grass and the

Effects of Dredging an Intracoastal Channel," University of Texas Marine

Science Institute, Institute of Marine Science, Austin, Vol. 9, 1963,

pp. 48-53.

Benthic chlorophyll a and diurnal oxygen productivity were measured in

turtlegrass beds containing Thalassia testudium and Diplanthera wrightii in

Redish Bay, Texas, before and after the dredging of an intracoastal canal.

Moderate values of photosynthesis (2 to 8 grams of oxygen per square meter per

day) were observed in the spring of 1959 following a period of shading by turbid dredge waters, but exceptionally high values (12 to 38 grams per square

meter per day) were recorded the following spring in those areas not smothered

with silt. Chlorophyll a in 1959 averaged 0.0338 gram per square meter but

increased to 0.68 gram per square meter the following summer.

85. ODUM, H.T., "Tropical Marine Meadows," Coastal Ecological Ecosystems of

the United States, H.T. Odum, B.J. Copeland, and E.A. McMahan, eds.,

Vol. 1, Conservation Foundation, Washington, D.C., June 1974, pp. 442-487.

The biology of tropical marine meadows and underwater grassy vegetation in

Florida, Texas, Puerto Rico, and the Bahamas is discussed.

86. O'GOWER, A.K., and WACASEY, J.W., "Animal Communities Associated with

Thalassia, Diplanthera, and Sand Beds in Biscayne Bay. I. Analysis of

Communities in Relation with Water Movements," Bulletin of Marine Science,

Vol. 17, No. 1, Mar. 1967, pp. 175-210.

Random samples collected from Diplanthera, Thalassia, and sand beds in the

shallow sublittoral zones at Key Biscayne and Virginia Key, Florida, indicated

both dissimilarities and similarities between the communities inhabiting these

environments. The data on occurrences and densities of species in these communities were analyzed, and associations of densities and selected environmental factors were determined.

27
87. ORPURT, P.A., and BORRAL, L.L., "The Flowers, Fruits and Seeds of Thalasaia testudinwn Koenig," Bulletin of Marine Science, Vol. 14, No. 2,

June 1964, pp. 296-302.

The flowers of turtlegrass (Thalassia testudinwn) are redescribed from

specimens collected in Biscayne Bay, Florida. An account is given of fruit

development and structure. Anatomy of the seed and the germination of turtlegrass are described for the first time.

88. ORTH, R.J., "Benthic Infauna of Eelgrass, Zostera marina, Beds,"

Chesapeake Science, Vol. 14, No. 4, Dec. 1973, pp. 258-269.

The infauna of Zostera beds in the Chesapeake Bay-York River estuary and

Chincoteague Bay was sampled in March and July 1970 using a corer. Sediments

were fine sand or very fine sand. Sediments varied from poor to moderately

well sorted and were positively correlated with the density of Zostera.

A total of 117 macroinvertebrate taxa were collected. Species number

decreased both up the estuary and seasonally from March to July. Movement of

epifaunal species from the sediments to the leaves in summer partly accounted

for this seasonal difference. This seasonal decrease was not noted at the

station farthest up the estuary where Zostera was scarce. Faunal similarity

as measured by three indices, indicates that the infauna of most Zostera beds

in the Chesapeake Bay area is similar, except at the upper estuary limits of

Zostera.

89. ORTH, R.J., "Destruction of Eelgrass, Zostera maririna, by the Cownose Ray,

Rhinoptera bonasus, in the Chesapeake Bay," Chesapeake Science, Vol. 16,

No. 3, Sept. 1975, pp. 205-208.

Destruction of Zostera beds in the York River, Virginia, is attributed to

the digging activities of the cownose ray (Rhinoptera bonasus). The physically stable Zostera habitat with high faunal diversity and density was

replaced by an unstable habitat with low faunal diversity and density.

90. ORTH, R.J., "The Role of Disturbance in an Eelgrass, Zostera mruina, Community," Ph.D. Dissertation, University of Maryland, College Park, Md.,

1975.

Eelgrass (Zostera nrina) beds in the Chesapeake Bay, Virginia, were

studied. Samples were taken in an intact eelgrass bed and within differentsized patches of eelgrass. Eelgrass areas were subjected to different levels

of physical disturbance. Exposed rhizome layers as a result of physical

disturbances increased habitat space and allowed a significant increase in

abundance of polychaete annelid (Polydora ligni). A predator exclusion cage,

simulating decreased disturbance, produced increased species diversity and

density.

Natural disturbance occurred with the invasion of cownose rays (Rhinoptera

bonasus) and toadfish (Opsanues tau). The rays removed large areas of eelgrass, resulting in much of the patchiness observed in eelgrass beds. The

infaunal density and diversity were significantly reduced in an eelgrass bed

destroyed by ray activity.

28
91. ORTH, R.J., "The Demise and Recovery of Eelgrass, Zostera ra?ina, in the

Chesapeake Bay, Virginia," Aquatic Botany, Vol. 2, No. 2, June 1976,

pp. 141-159.

From 1971-74 eelgrass (Zostera marina) declined 36 percent. Evidence

indicating the loss was determined from aerial photos and ground-truth reconnaissance. The decline is attributed to the cownose ray, human disturbance,

and a rise in water temperature.

92. ORTH, R.J., "Effect of Nutrient Enrichment on Growth of the Eelgrass,

Zostea marina, in the Chesapeake Bay, Virginia, USA," Marine Biology,

Vol. 44, No. 2, 1977, pp. 187-194.

The addition of two commercial fertilizers had a positive effect on the

growth of Zostera marina in the Chesapeake Bay. There was a significant

increase in the length, biomass, and total rffumber of turions in fertilized

plots compared with controls. This short-term field experiment suggests that

Zostera beds in the Chesapeake Bay are nutrient-limited, that the growth form

of Zostera may be related to the sediment nutrient supply, and that Zostera

may competitively exclude Ruppia maritina by the shading of the light.

93. ORTH, R.J., "The Importance of Sediment Stability in Seagrass Communities," Ecology of Marine Benthos, B.C. Coull, ed., University of South

Carolina Press, Columbia, S.C., 1977, pp. 281-300.

Dense seagrass beds, such as Zostera in the Chesapeake Bay, stabilize sediments, promote diverse and abundant benthic fauna, and protect fauna from

predation from blue crabs.

94. PATRIQUIN, D.G., "Estimation of Growth Rate, Production and Age of the

Marine Angiosperm Thalassia testudinum Konig.," Caribbean Journal of

Science, Vol. 13, No. 1-2, Institute of Marine Science, University of

Puerto Rico, Mayaguez, June 1973, pp. 111-123.

There is a linear relation between average growth rate and the average

maximum leaf length of Thalassia. The ratio production-to-standing crop (wet

weight including epiphytes) tends to be constant. New foliage is developed at

intervals of about 15 days. The age, growth rate, and production of underground parts can be estimated by counting leaf scars.

95. PATRIQUIN, D.G., "Migration of Blowouts in Seagrass Beds at Barbados and

Carriacou West Indies and its Ecological and Geological Implications,"

Aquatic Botany, Vol. 1, Elsevier Scientific Publishing Company, Amsterdam,

The Netherlands, 1975, pp. 163-189.

Blowouts are grass-free depressions within seagrass beds at Barbados and

Carriacou and reported in the literature to be common elsewhere in the

Caribbean region. They are typically crescent-shaped in plan view with the

convex side seaward, and are characteristic of elevated seagrass beds in

regions of moderate to strong wave action. The seaward edge is steep and

exposes rhizomes of Thalassia; the leeward edge slopes gently upward to the

seagrass plateau and is usually colonized by Syringodium. The general morphology of the blowouts, the zonation of organisms across them, and the existence at some blowouts of a lag deposit of cobble-sized material at the scarp

base continuous wth a rubble layer below the seagrass carpet suggest that the

blowouts "migrate" awrb lerelowthe s carp erosion and of the advance

29
of Syringodium onto the blowout floor over a period of 1 year confirm this. It

is estimated that in the region of blowouts any one point will be recurrently

eroded and restabilized at intervals of 5 to 15 years. Such processes limit

successional development of the seagrass beds, disrupt sedimentary structures,

and may result in deposits much coarser than those characteristic of the sandy

seagrass carpet.

96. PENHALE, P.A., "Primary Productivity, Dissolved Organic Carbon Excretion,

and Nutrient Transport in an Epiphyte-Eelgrass (Zostera marina) System,"

Ph.D. Dissertation, North Carolina State University, Raleigh, N.C., 1977.

The biomass, productivity (14C), and photosynthetic response to light and

temperature of eelgrass (Zostera marina) and its epiphytes were measured in a

shallow estuarine system near Beaufort, North Carolina, during 1974. The peak

of the biomass (aboveground) was measured in March. Eelgrass and epiphyte

productivity was low during the spring and early summer, peaked during late

summer and fall, and declined during the winter.

The release and cycling of dissolved organic carbon by eelgrass and its

epiphytic community were, examined by measuring the excretion of dissolved

organic carbon by eelgrss heavily colonized by epiphytes, the excretion by

relatively uncolonized eelgrass, and the excretion by an epiphytic community

attached to an artificial substrate. The excretion rates by eelgrass and

epiphytes were low compared to total carbon fixation. The annual primary

production and dissolved organic carbon excretion by phytoplankton, smooth

cordgrass (Spartina alterniftora), eelgrass and its epiphytes were estimated. Eelgrass and its epiphytes contributed 47 percent of the total annual

primary production and 14 percent of the total excreted material. Thus, the

eelgrass and epiphytes play an important role in the primary productivity and

the dissolved organic carbon cycles in this estuarine system.

97. PENHALE, P.A., and THAYER, G.W., "Uptake and Transfer of Carbon and Phosphorus by Eelgrass (Zostera marina L.) and its Epiphytes," Joural of

Experimental Marine Biology and Ecology, Vol. 42, No. 2, Jan. 1980,

pp. 113-123.

The uptake of carbon and phosphorus by eelgrass (Zostera nmarna) and its

epiphytes under laboratory conditions was examined using 14C and 32p in partitioned chamber experiments. Both the carbon and phosphorus were taken up by

eelgrass roots and subsequently transferred through the plants to epiphytes on

the grass blades. The data suggested that only a small part of the carbon

fixed in photosyntheses is supplied through the roots and rhizomes. There was

very little net transfer of phosphorus through the plants during the 12-hour

experiments; the most active movement of phosphorus was from the water into

the roots where most of the material remained. Phosphorus uptake depended on

the concentration of dissolved inorganic phosphorus in the medium. An increase in phosphorus concentration of the medium resulted in increased uptake

rates; however, the proportion of accumulation of 3 2 p in the roots, leaves,

and epiphytes remained similar. Experimental design should be carefully considered when comparing the results of various phosphorus uptake studies. The

data indicated that a close relationship exists between eelgrass and its epiphytic community; 15 to 100 percent of the phosphorus released by the leaves

was taken up by the epiphytes.

30
98. PHILLIPS, R.C., "Comprehensive Bibliography of Zostera marvina," Special

Scientific Report, Wildlife No. 79, U.S. Fish and Wildlife Service,

Bureau of Sport Fish Wildlife, Washington, D.C., Jan. 1964.

This is an alphabetical listing by author of worldwide research on eelgrass (Zostera marina) prior to 1964. Abstracts are not included.

99. PHILLIPS, R.C., "On Species of the Seagrass Halodule in Florida," Bulletin of Marine Science, Vol. 17, No. 3, Sept. 1967, pp. 672-676.

Three vegetative leaf characters (leaf width, apex morphlogy, and the

presence or absence of lacunae around the midvein), previously used to

separate species of the seagrass Halodule, are shown to vary on the same

plant, and also on plants in different environments, to such a degree that

they cannot be used as species characters. Phillips' opinion is that all

Halodule plants he observed from Florida waters belong to Hatodule wrvightii

Ascherson.

100. PHILLIPS, R.C., "Ecological Life History of Zostera rarina L. (Eelgrass)

in Puget Sound, Washington," Ph.D. Dissertation, University of

Washington, Seattle, Wash., Aug. 1972.

This report includes observations and experiments on the occurrence as

well as vegetative and reproductive behavior of eelgrass in Puget Sound. Eelgrass was found from Admiralty Head on Whidbey Island, on both sides of Puget

Sound, to east of a line from the Nisqually Flats to Henderson Bay in southern

Puget Sound. Eelgrass was absent west of this line, and on the east side of

Whidbey Island growth was patchy. Eelgrass in the Puget Sound is limited in

depth to -6.8 meters. Transplants placed at -8.0, -9.6, and -10.6 meters

indicated that vegetative growth at depths greater than -6.6 meters was

favorable.

Intertidal turions were three to four times denser than subtidal turions,

but maintained an average biomass approximately equal to that of subtidal

turions. Rhizome biomass exceeded leaf biomass in fall, winter, and spring.

Minimum vegetative biomass was found in winter; maximum biomass was found in

summer. Vegetative activities of root and leaf growth were initiated in

February, following a 2- or 3-month period of relative growth dormancy. The

stimulus for vegetative and floral initiation in late winter is a photoperiodic response. Reproductive biomass was greatest from May through

August. The maximum vegetative biomass occurred after the initial appearance

of maximum reproductive biomass. By early August fruits began maturing and in

late August and in September seeds were formed.

Seed germination occurred throughout the year, but predominantly from

April to July, following the summer of their formation. Only those seeds

which germinated from March to July attained sufficient growth to survive the

erosive effect of fall storms. Only 1 to 6 percent of the seed crop germinated in normal strength seawater (30 parts per thousand), while up to 70 percent of the seeds germinated in dilute salinities. An eelgrass meadow was

maintained by seed germination and vegetative growth. The latter method was

the more significant. Geographic dispersal was by seed dissemination from

floating reproductive turions.

31
101. PHILLIPS, R.C., "Temperate Grass Flats," Coastal Ecological Systems of

the United States, B.J. Copeland, E.A. McMahan, and H.J. Odum, eds.,

Conservation Foundation, Washington, D.C., Vol. 2, June 1974, pp. 244-

299.

Five species of seagrasses are reported from temperate North America.

Zostera marina is the most important species with Halodule wrightii, Phyllospadix sconleii, P. to'reyi, and Ruppia nw'itima of less importance. The distribution and ecology of eelgrass in the temperate zone of the world are

discussed.

102. PHILLIPS, R.C., "Transplantation of Seagrasses, with Special Emphasis on Eelgrass, Zostera maina L.," Aquaculture, Vol. 4, Oct. 1974, pp. 161-

176.

The history of transplanting seagrasses is given. Seagrass field planting methods are needed due to the extremely high productivity of seagrasses

and the perturbations they are subject to. Data from experimental plantings

indicate (a) distinctions in varieties based on leaf dimensions are invalid,

(b) the possibility of local physiological race distinction, (c) the depth

limit of eelgrass is due to a lack of suitable light deeper than a certain

minimum depth, and (d) eelgrass seedlings require a higher light intensity

than is present deeper than a certain minimum depth. Transplanting experiments provided much more information concerning seagrass biology than just

planting method information.

103. PHILLIPS, R.C., "Seagrass, Food in the Inshore Coast," Pacific Search,

Vol. 9, No. 9, Sept. 1975, pp. 2-4.

This is a study of seagrass as food for marine life. Seagrass at one

time was not considered important to marine life, but it is now recognized as

important not only to marine life but also to man. Seagrass is adversely

affected by sewage. This project studied the annual growth and development

cycle of eelgrass to develop planting methods for any season, and to develop

new eelgrasses and turtlegrasses that are more adapted to man-influenced

environment.

104. PHILLIPS, R.C., "Preliminary Observations on Transplanting and a Phenological Index of Seagrasses," Aquatic Botany, Vol. 2, No. 2, June 1976,

pp. 93-101.

Transplanting of seagrasses yields basic biological information on tolerances to changes and extremes of water temperature and salinity, substrate,

and chemical pollutants. Reciprocal transplants across tidal zones or across

latitudinal distances can be used to distinguish whether responses represent

phenotypic plasticity or ecotypic differentiation. Transplanting also represents the ability to maintain, create, or re-create seagrass meadows where

human activity is increasing. It is important to know the phenology of seagrasses used in transplanting. A preliminary phenological index is given.

105. PHILLIPS, R.C., "Seagrasses and the Coastal Marine Environment," Oceanus,

Vol. 21, No. 3, 1978, pp. 30-40.

Seagrasses create a diversity of habitats and substrates, providing a

structured habitat from a structureless one. Because of their structure and

physiology, seagrasses perform a wide assortment of biological and physical

32
functions in the coastal environment. They tolerate a wide range of salinities and water temperatures. The most important role of seagrasses in the

food chain is their formation of detrius. There is an important relationship

between seagrass detrius and nutrient cycling within and across ecosystem

boundaries. Seagrass leaves act as a baffle that increases the rate of particulate sedimentation, preferentially concentrating the finer particles and

stabilizing the underlying sedimentary deposits. Despite the ability of sea--

grasses to adapt to a fluctuating environment, several, human-related activities threaten the hardy plants.

106. PHILLIPS, R.C., "Planting Guidelines for Seagrasses," CETA 80-2, U.S.

Army, Corps of Engineers, Coastal Engineering Research Center, Fort

Belvoir, Va., Feb. 1980.

An intensive review was made of the historical and present work on

transplanting seagrasses, including eelgrass, turtlegrass, shoalgrass,

manateegrass, and ditchgrass. The best seasons, recommended methods of

transplanting, and propagules to use for each species are listed for the

coasts of the United States. Some of the more important environmental

parameters which directly influence successful transplanting are reviewed.

107. PHILLIPS, R.C., and McROY, C.P., eds., Handbook of Seagrass Biotogy: An

Ecosystem Perspective, 1st ed., Garland, New York, 1980.

This book includes discussions of leaf morphology, anatomy, phenology,

taxonomy, transplanting methods, culture methods, remote sensing of seagrass

beds, productivity, faunal relationships, and detritus-decomposition relationships of seagrasses.

108. PHILLIPS, R.C., and SHAW, R.R., "Zostera noltii Hornem, in Washington,

U.S.A.," Syesis, Vol. 9, 1976, pp. 355-358.

Evidence is presented to substantiate the use of the specific epithet

Zostera noZtii for a second species of Zostera in Washington State. The

authors conclude that these plants do not constitute a new species, i.e.,

Z. americana.

109. PHILLIPS, R.C., VINCENT, M.K., and HUFFMAN, R.T., "Habitat Development

Field Investigation, Port St. Joe Seagrasses Demonstration Site, Port St.

Joe, Florida," Report No. TR D-78-33, U.S. Army Engineer Waterways

Experiment Station, Vicksburg, Miss., July 1978.

Shoalgrass (Hatodule wr, ightii) was transplanted at Port St. Joe, Florida,

using the plug technique. Two sizes of plugs were removed from a natural

meadow and planted on coarse-grained, dredged material at three different

spacings. Many of the transplants grew significantly before the project

failed nearly 13 months after planting. Best growth was obtained with 375-

square centimeter plugs planted on 0.9-meter centers. The reason for the

project failure is not known.

110. PHILLIPS, R.C., et al., "HaZoduZe wr7ightii Ascherson in the Gulf of

Mexico," Contributions in Marine Science, Vol. 18, Sept. 1974, pp. 257-

261.

An abundance of flowering material and fruiting material of Halodule was

found in Redfish Bay, near Port Aransas, Texas, in May and July 1974. The

33
flowers agreed with the description of flowers given for H. wrightii in den

Hartog (1970) and since leaf tip morphology varied from bidenate to tridentate

in clonal material, it is concluded that this material is H. w .ightii. It is

also possible that all Halodule in the Gulf of Mexico is H. woightii. The

authors question the practice of creating new species in the genus Halodule

based solely on whether vegetative leaf tips are bidentate or tridentate.

111. RANWELL, D.S., et al., "Zoetera Transplants in Norfolk and Suffolk, Great

Britain," Aquaculture, Vol. 4, No. 2, Oct. 1974, pp. 185-198.

Zostera noltii and Zoster' marina var. anguetifolia turfs have been

transplanted on sheltered estuarine mudflats in carefully selected areas in

Norfolk and Suffolk, Great Britain. Transplanting with turfs can be done on

suitable mudflats where mud surface changes in level of at least +7 or +3

centimeters per week occur. Growth is favored in areas where a close balance

between erosion and accretion occurs. Field scale transplanting of Z. noltii

appears feasible in areas approaching I hectare in size at a cost of about

$1,000 per hectare (1973 prices).

112. RINER, M., "A Study on Methods, Techniques, and Growth Characteristics

for Transplanted Portions of Eelgrass (Zostera marina)," M.S. Thesis,

Adelphi University, Garden City, New York, 1976.

Comparison was made of three transplant techniques for eelgrass (Zoetera

marina). More than 2,000 plug parts was planted. Survival was techniquedependent and varied from 100 percent for plugs to 36 percent for individual

shoots, after 2 months. Miniplugs (survival rate of 71 percent) were best

because of ease in harvesting, transporting, and planting. Large initial

transport size resulted in greater production of material per unit time.

Treatment of single shoots with the hormone, naphthalene acetic acid, was not

advantageous. The use of a slow-release fertilizer resulted in greater dry

weight values for the shoot and rhizome material. Transplants also showed a

difference in growth response once removed from the established community.

Transplant success can be achieved without anchoring devices. Areas with

shifting sediments and current velocities approaching I knot prevent survival

beyond 4 months.

113. ROESSLER, M., "Environmental Changes Associated with a Florida Power

Plant," Marine Pollution Bulletin, Vol. 2, No. 6, June 1971, pp. 87-90.

Damage to the biota of Biscayne Bay by the heated effluent of a powerplant is demonstrated. Algae and seagrasses were replaced by blue-green

filamentous algal mats; seasonal recovery was slow and the affected areas

contained fewer kinds and smaller numbers of animals. Increased temperature

was the chief cause.

114. ROGERS, R.G., "Seagrasses Revegetation in Escambia Bay, Florida," Proceedings of the First Annual Conference on Restoration of Coastal Vegetation in Florida, Hillsborough Community College Environmental Study

Center, Tampa, Fla., May 1974, pp. 21-26.

Four species of seagrasses (Vallisneria americana, Ruppia ma'itima,

Halodule wrightii, and ThaZlassia testudinum) were planted in three parts of

Escambia Bay. The outcome of the project is not given. Future experimental

trials of artificial seaweed are described.

34
115. SAND-JENSEN, K., "Biomass Net Production and Growth Dynamics in an Eelgrass (Zoetea marina L.) Population in Vellerup Vig, Denmark," OpheZia,

Vol. 14, Hlelsingaer, Denmark, Nov. 1975, pp. 185-201.

The biomass of an eelgrass population in Vellerup Vig, Denmark, showed a

seasonal pattern, March to October 1974, with the peak in August. Biomass of

leaves and flowering turions was quadrupled; biomass of rhizomes doubled from

March to August. The maximum total biomass was 433 grams dry weight per

square meter. The leaf population was determined by a leaf-marking technique,

which also made it possible to estimate the rhizome population. From 9 April

to 16 October 1974, the leaf production was 856 grams dry weight per square

meter and the rhizome production 241 grams dry weight per square meter, which

made a total of 1,097 grams dry weight per square meter. The dominance of

leaf production, though leaf and rhizome biomass were of the same magnitude,

resulted from a higher turnover rate of leaves .(1.8 percent per day) than of

rhizomes (0.7 percent per day). On the average a new leaf was produced on

each turion every 14 days. The lifespan of the leaves was about 56 days.

Total radiation and not temperature seemed to control leaf production. The

maximum leaf production rate of 7.9 grams dry weight per square meter per day

in mid-June coincided with maximum radiation. The total production was 3.8

times the net increase of total biomass and 2.5 times the maximum total

biomass.

116. SCHUBEL, J.R., "Some Comments on Seagrasses and Sedimentary Processes,"

Special Report No. 33, John Hopkins University, Chesapeake Bay Institute,

Baltimore, Md., Nov. 1973.

This report provides a brief review of some of the important relationships between seagrasses and sediments, and indicates a few of the problem

areas where further research is needed.

117. SCOFFIN, T.P., "The Trapping and Binding of Subtidal Carbonate Sediments

by Marine Vegetation in Bimini Lagoon, Bahamas," Journal of Sediment

Petrology, Vol. 40, No. 1, Mar. 1970, pp. 249-273.

In the shallow-water lagoon of Bimini, Bahamas, the following plants are

sufficiently abundant to influence sedimentation locally: red mangroves

(Rhiaophora mangle), turtlegrass (Thatassia teatudinw), macroscopic green

algae (PenicilZue, &ztophora, Hatimeda, !ftipocephalus, and Udotea) and microscopic red, green and blue-green algae-forming surface mats of intertwining

filaments (Laurencia, Enteomorpha, Lyngbya, and Schiaothrix). Plants were

observed under conditions of tidal currents and artificial unidirectional

currents produced in an underwater flume, and measurements were made of the

abilities of the plants to trap and bind the carbonate sediment. The density

of plant growth is crucial in the reduction of current strength at the

sediment-water interface. The most effective baffles are Rhizophora roots

exposed above the sediment, dense Thalassia blades and Thalassia blades with

dense epiphytic algae, Lauwencia intriicata and PoZyeiphonia havanensis. All

three types can reduce the water velocity from a speed sufficiently high to

transport loose sand grains along the bottom in clear areas (30 centimeters

per second) to zero at the sediment-water interface in the vegetated areas.

The strongest binders of sediment are the roots of Rhizophora and Thalassia.

These two hardy plants trap and bind sediment for a sufficient time to produce

an accumulation higher than in nearby areas without dense mangroves or grass.

Macroscopic green algae growth is not sufficiently dense, and the holdfasts

35
are too weak to appreciably affect the accumulation of sediment although they

provide a degree of stabilization to the substrate. Algal mats trap sediment

chiefly by adhesion of grains to the sticky filaments. Their ability to

resist erosion by unidirectional currents varies considerably depending on mat

type, smoothness of surface and continuity of the cover. The intact areas of

dense Enteromorpha mats can withstand currents five times stronger than those

rtat erode loose unbound sand grains. Premature erosion of mats by currents

occurs at breaks in the mat surface caused by the burrowing action of animals. Algal mats were found to be ephemeral features and consequently do not

build up thick accumulations of sediment as do dense grass and mangroves. The

thickest accumulation of sediment in the lagoon correlate with deepest bedrock

surfaces. The distribution of many plants in the lagoon is directly and

indirectly controlled by the depth to bedrock; e.g., red mangroves on high

bedrock, turtlegrass in sediment-filled depressions.

118. SOMERS, G.F., ed., "Seed-Bearing Halophytes as Food Plants," Report No.

DEL-SG-3-75, College of Marine Studies, University of Delaware, Newark,

Del., June 1974.

The report discusses seed-bearing halophytes as food sources for man and

domesticated animals. Contributions covered such subjects as domestication of

wild rice, use of seagrasses and terrestrial halophytes as food plants, adaptation of present crops to saline habitats, and problems in managing saline

soils.

119. STEVENSON, J.C., and CONFER, N.M., "Summary of Available Information of

Chesapeake Bay Submerged Vegetation," Report No. FWS/OBS-78/66, Office of

Biological Services, U.S. Fish and Wildlife Service, Washington, D.C.,

Aug. 1978.

Submerged aquatic species tend to inhabit the shallow, shoreline areas of

the bay and its subestuaries, primarily limited to depths of 3 meters or less.

Species vary as to salinity and temperature tolerance, morphology, preferred

bottom substrate, susceptibility to chemical pollutaits, and general distribution. There are approximately 11 species of submerged aquatic vegetation

dominant in the waters of the Chesapeake Bay. Submerged aquatic flora constitutes the principal source of food for waterfowl and some fish; the flora

provides direct and indirect food and shelter for many of the small host

organisms that are eaten by fish and other predators. The spawning activities

of certain organisms require submerged aquatic vegetation. The vegetation

purifies the water by removing various noxiout substances and returning

oxygen, shades the underlying waters and sediments from solar heating, and

provides an important source of detritus. Submerged aquatics help stabilize

sediments and reduce shoreline erosion.

120. TAYLOR, J.L., SALOMAN, C.H., and PREST, K.W., Jr., "Harvest and Regrowth

of Turtle Grass (Thalassaa testudinm) in Tampa Bay, Florida," Fisheies

ulZletin, Vol. 71, No. 1, Jan. 1973, pp. 145-148.

A comparison of leaf growth and new leaf production in plots of cut and

uncut turtlegrass (Thatassia teetudinwn) indicated that plants suffered no

damage when harvested twice during a 6-month season in Roca Ciega Bay (Tampa

Bay), Florida. In deeper or warmer waters where the growing season is protracted, three or more cuttings per year may prove practical.

36
121. THAYER, G.W., and PHILLIPS, R.L., "Importance of Eelgrass Beds in Puget

Sound," Marine Fisheries Review, Vol. 39, No. 11, Nov. 1977. pp. 18-22.

Eelgrass beds in Puget Sound, Washington, are important to many invertebrates. A partial list of invertebrates commonly collected in the Puget Sound

beds and a list of commercial or recreational invertebrates and vertebrates

are given. Invertebrates of the eelgrass beds are described as small

epiphytes, attached fauna, motile users, and resting swimmers. The usefulness

of the beds for food and shelter is discussed and related to the aquatic food

chain.

122. THAYER, G.W., and STUART, H.H., "The Bay Scallop Makes Its Bed of Seagrass," Marine Fisheries Review, Vol. 36, No. 7, July 1974, pp. 27-30.

The bay scallop (Argopecten irradiane), important commercially in eight

Atlantic coast states, is more often associated with seagrass. In North

Carolina one or more years of good scallop harvest have been followed by

several years of poor harvest, the most recent being 1970-72. Commercial

dredging and trawling for scallops and fish in shallow estuaries disrupt the

vegetation and bottom, and this may impede the regrowth of the grass to which

larval bay scallops attach. Commercial dredging significantly decreases both

scallop and grass density, and it is suggested that annual or biannual rotation of scallop harvesting techniques might increase scallop productivity.

12. THAfER, G.W., ADAMS, S.M., and LaCROIX, M.W., "Structural and Functional

Aspects of a Recently Established Zostera mtr7ina community, "Estuarine

Research, Vol. 1, Academic Press, New York, 1975, pp. 518-540.

The value of eelgrass productivity to an ecosystem has been recognized

for more than 50 years but little quantitative information is available. The

epifaunal and infaunal invertebrates and the fishes inhabiting a grass bed in

the Newport River estuary are dominated by only a few species. The density

and biomass of these groups are greater than in the adjacent unvegetated

areas. Fishes appeared to have some control over the density of the epifaunal

community. The macrofauna consume an amount of energy equivalent to 55 percent of the net production of eelgrass, phytoplankton, and benthic algae in

the bed. There is an excess of plant production in the bed, a part of which

is increasing the organic content of the sediments. The remainder is exported. This export may be highly significant to the tropic function of the

shallow estuarine system.

124. THAYER, G.W., ENGLE, D.W., and IaCROIX, M.W., "Seasonal Distribution of

Changes in the Nutritive Quality of Living, Dead and Detrital Fractions

of Zoatera marina," Journal of Epe.imental Marine Piology and Ecolopy,

Vol. 30, No. 2, Nov. 1977, pp. 109-127.

Samples of eelgrass (7ostera marinta) were collected monthly from December

1974 to December 1975 in a shallow embayment near Beaufort, North Carolina,

and separated into living leaves, dead leaves, and detritis. Each component

was analyzed for dry weight, organic matter, inorganic and organic carbon,

nitrogen and amino compounds.

The standing crop of living and dead leaves reached a maximum April

through June. Detrital material peaked in December, April, and July to

September. Inorganic carbon varied seasonally and represented 14, 24, and 30

percent of the total carbon associated with the living and dead leaves and

37
detrital fragments, respectively. Organic carbon was a decreasing proportion

of the dry weight of the three fractions on a dry weight basis; there was a

significant increase on an ash-free dry weight basis for the dead blades.

During senescence there was a loss of nitrogen from the leaves and an increase

in the nitrogen of the detritus relative to the dead leaves. The relative

proportions of nitrogen-acetyl-glucosamine, nitrogen and organic carbon were

all higher in the fall and winter.

125. THAYER, G.W., WOLFE, D.A., and WILLIAMS, R.B., "The Impact of Man on Seagrass Ecosystems," American Scientist, Vol. 63, 1975, pp. 288-296.

This report discusses seagrasses, especially Zostera and Thalassia and

their distribution, environmental tolerances, and productivity. Coastal

development, including dredging and pollution, can destroy seagrass beds by

reducing light penetration, changing the redox potential of anerobic soils, or

by adding toxins to the seagrass ecosystem. Other environmental disturbances

are crude oil spillage, heated water discharge, and commercial fishing. The

destruction of seagrass beds can have far-reaching impacts on organisms

dependent on the grasses and detritus.

126. THOMAS, L.D., MOORE, D.R., and WORK, R.C., "Effects of the Hurricane

Donna on the Turtle Grass Beds of Biscayne Bay, Florida," Bulletin of

Marine Science, Vol. 11, No. 2, June 1961, pp. 191-197.

The dry and wet weight of Thalassia testudinuw washed ashore at Biscayne

Bay during Hurricane Donna in 1960 is estimated. Agents destructive to

turtlegrass (other than wind) are discussed, and additional observations are

included of hurricane damage to the turtlegrass beds of the Bahama banks.

127. THOMAS, M.L.H., and DUFFY, J.R., "Butoxyethanol Ester of 2, 4-D in the

Control of Eelgrass (Zostera marina L.) and its Effects on Oysters

(Crassost'ea virginica gmelin) and other Benthos," Proceedings of the

Northeastern Weed Control Conference, Vol. 22, 1968, pp. 168-194.

Eelgrass (Zoste'a marina) growth has a detrimental effect on oyster farming in eastern Canada. Results of preliminary experiments in chemical and

mechanical control of eelgrass showed that mechanical control attempts by

cutting or digging were short-lived, expensive, and frequently a failure. In

earlier trials with various herbicides, only one was effective at reasonable

concentrations without causing unacceptable mortalities of associated biota.

This was a granular formulation of the butoxyethanol ester of 2N 4-D. Literature indicates that concentrations found in the field are not expected to

harm animals.

128. T1IORHAUG, A., "Transplantation of the Seagrass Thalassia testudinum

Konig," Aquaculture, Vol. 4, 1974, pp. 177-183.

The article covers gathering seed pods of turtlegrass, and preparing and

planting the seeds. Laboratory seeding resulted in poor plant survival and

near failure. However, field trials in Biscayne Bay, Florida, were successful

with approximately 70-percent survival of seedlings 8 months after planting.

129. THORHAUG, A., "Transplantation Techniques for the Seagrass Thalassia

testudinutm," Sea Grant, Technical Bulletin No. 34, University of Miami,

Miami, Fla., June 1976.

Turtlegrass (Thalasia testudinum) can be planted throughout the Gulf of

Mexico, southeast Florida coast, and the Caribbean. Two planting methods,

38
seeding and plugging, are feasible, and the advantages of each are discussed. The seeding method appears to be most advantageous for dredged

material stabilization. The plugging method is advantageous because plugs car.

be taken from mature beds throughout the U.S. coastal waters, whereas seeds

are sparse or absent in many places. Plugging also may be done year round,

while seeding is best in fall or spring.

130. THORHAUG, A., and AUSTIN, C.B., "Restoration of Seagrasses with Economic

Analysis," EnvironmentaZ Conservation, Vol. 3, No. 4, 1976, pp. 259-267.

Planting of seagrasses by use of plugs, turfs (sods), turions (shoots),

and seeds is briefly described from a review of some pertinent world literature. The economic analysis evidently applies only to the cost of seeding

Thalassia. Seeding densities to yield good cover in 2.5 years cost approximately $25,000 per 10,000 meters. If the same amount of cover is to be

obtained in 0.8 year the cost will be three to five times greater.

131. THORHAUG, A., and HIXON, R., "Revegetation of Thalassia testudinwn in a

Multiple-Stressed Estuary, North Biscayne Bay, Florida," Proceedings of

the Second Annual Conference on Restoration of Coastal Vegetation in

Florida, Hillsborough Community College Environmental Study Center,

Tampa, Fla., May 1975, pp. 12-27.

Plantings of Thalassia testudinwn were made in the multiple-stressed

estuary of North Biscayne Bay, Florida. Seeds were gathered by divers and

tested in the varying condition of light, temperature, and flowing seawater.

Seeds and seedlings were planted at eight field sites. The survival rate,

growth, rhizome frequency, and planting techniques are discussed.

132. THORHAUG, A., BEARDSLEY, G., and HIXON, R., "Large Scale Transplantation

of Thalassia in South Florida," Proceedings of the First Annual Conference on Restoration of Coastal Vegetation in Florida, Hillsborough

Community College Environmental Study Center, Tampa, Fla., May 1974,

pp. 18-21.

The marine grass Thalassia testudinum has been transplanted by sprigs on

a small scale by several investigators in Florida. Sprig planting is timeconsuming and has limited value. Only rarely does a plant without the apical

meristem produce a new short shoot and thus grow laterally. The alternative

of seed planting had not been tested until this experiment.

Fruit was collected manually by scuba divers. Seeds were dehisced by

mechanical shock of freshweater and immediately cleaned and separated from

fruit pod. Seedlings were rapidly transported to the planting area in aerated

running seawater. Various concentrations and the soak time of napthalene

acetic acid were tested. Seedlings were kept agitated in seawater until

planted. Two 150-meter transects were established at Turkey Point, Biscayne

Bay, Florida. These transects included three major zones of regrowth: Halodule wrightii, green siphonaceous algae, and bare peat. Part of the plants were anchored with plastic anchors, and part were without anchors. Planting

was at 0.5, 0.25, and 0.1 meter in a pattern repeated every 50 meters. Approximately 15,000 seedlings was planted. Growth was vigorous. Mean growth of

blades after 8 months was 16.5 centimeters. Approximately 80 percent of the

plants remained in position; 10 percent washed out and were found in the

immediate area of transplanting.

39
133. VanBREEDVELD, J.F., "Transplanting of Seagrasses with Emphasis on the

Importance of Substrate," Florida Marine Research Publication No. 17,

Florida Department of Natural Resources, Marine Research Laboratory, St.

Petersburg, Fla., Nov. 1975.

Seagrass transplant experiments have emphasized the use of anchoring

devices rather than the suitability of substrate. Thalassia needs an anaerobic environment, Halodule an aerobic substrate; Syringodium can thrive in

either substrate. Transplants should be clumps of four to seven shoots with a

few intact rhizomes. The original substrate is transferred with the plants.

Plantings should be close together thus, offering the roots and rhizomes a

favorable environment from the beginning and allowing them gradually to stabilize the surrounding area. Additionally, at least three rows should be

planted for increased protection and transplant success.

134. WAYNE, C.T., "Sea and Marsh-Grasses: Their Effect on Wave Energy and

Near-Shore Sand Transport," M.S. Thesis, Florida State University,

College of Arts and Sciences, Tallahassee, Fla., Sept. 1975.

Sea and marsh grasses were found to reduce wave heights by as much as 71

percent and wave energy by 92 percent. Binding and trapping of sediments by

the grass may modify the pattern of deposition. The effect of artificial seagrass on wave energy and near sediment transport was explored. The placement

of offshore, artificial seagrass beds may influence nearshore sand transport. Artificial seagrass may decrease wave energy due to bending of the

fronds, increased bottom drag, internal deformation and refraction.

A dense bed of seagrass can reduce total wave power and modify the wave

approach angle. Through an adjustment of total wave power or B angle, alteration of the littoral component of wave power may be achieved with a corresponding reduction of erosion rates.

135. WELDON, L.W., BLACKBURN, R.D., and HARRISON, D.S., Co"Mon Aquatic Weeds,

Dover Publications, Inc., New York, 1973.

This handbook was compiled to serve as a basis for the identification of

the more common aquatic plants including widgeongrass and Vallisneria. The

various plants have been observed, photographed, and, where necessary illustrated to show the more distinguishable characteristics. Each plant and its

natural habitat, distribution, and importance are discussed.

136. WOOD, E.J.F., ODUM, W.E., and ZIEMAN, J.C., "Influence of Seagrasses on

the Productivity of Coastal Lagoons," Proceedings of Memorial S mposiwn

International on Coastal Lagoons, Institute De Biologica, Universidad

Nacional, Autonoma de Mexico, Nov. 1967, pp. 495-502.

Seagrasses in coastal lagoons function to control or modify the ecosystem

in the following ways:

(a) Serve as food for a very limited number of organisms such as

the parrotfish, surgeonfish, Australian garfish, the Queen conch,

sea urchins, and some nudibranch. The green sea turtle formerly

grazed heavily on the turtlegrass. It has been found, however, that

certain urchins grind up the seagrasses but do not appear to digest

them; this may apply to other animals which appear to graze on the

grass.

40
Cb) Serve as hosts for large numbers of epiphytes which are

grazed extensively, for example, by the mullets. These epiphytes

may be comparable in biomass with the seagrasses themselves,

(c) Provide large quantities of detrital material which serves as

food for certain animal species and for microbes which in turn are

used as food by larger animals.

(d) Provide organic matter to initiate reductipn and an active

sulfur cycle.

(e) Bind the sediments and prevent erosion. This also preserves

the microbial flora of the sediment and the sediment-water

interface.

(f) Collect organic and inorganic material by slowing down currents and stabilizing the sediments.

The seagrasses have a rapid rate of growth (up to 9 millimeters per day,

average 2 to 4 millimeters per day) and produce between 2.2 and 10.0 grams of

dry leaf per square meter per day.

137. YOUNG, D.K., and YOUNG, M.W., "Regulation of Species Densities of Seagrass-associated Macrobenthos: Evidence from Field Experiments in the

Indian River Estuary, Florida," Jou'nal of Marine Research, Vol. 36,

No. 4, Nov. 1978, pp. 569-593.

Field experiments in the Indian River estuary, Florida, were initiated in

the seagrass beds, HTaoduZe wrightii, to test effects of (a) excluding predators by caging, (b) enclosing predators inside cages, (c) adding dense populations of suspension feeders, (d) providing organic enrichment, and (e) removing seagrass blades.

The 11 most abundant species were selected for statistical testing of

responses to the experimental treatments. Analyses showed that macrobenthic

species differed markedly in their responses to the various treatments over a

period of 1 year. Several species increased in densities with organic enrichment; whereas, some species increased in densities as a result of protection

by the predator exclusion cage. When seagrass blades were clipped, some

species increased in densities while others had decreased densities. These

variations in response did not consistently correspond to taxonomic groupings

or feeding types.

138. ZIEMAN, J.C., "Origin of Circular Beds of Thalassia (Spermatophyta:

Hydrocharitaceae) in South Biscayne Bay, Florida, and their Relationship

to Mangrove Hammock," Bulletin of Marine Science, Vol. 22, No. 3,

Sept. 1972, pp. 559-574.

Aerial photos of a mangrove shoreline and an adjacent estuarine area in

southwestern Biscayne Bay, Florida, showed the presence of numerous c~rcular

to teardrop-shaped areas. The circular areas on shore are hammocks of mangroves and other tropical trees, and they are over depressions in the bedrock

which are filled with mangrove peat. The circular areas in the estuary are

beds of Thalassia teetudinwn. Thalassia beds are often surrounded by a white

halo of worm and callianassid burrows. The effect of sediment depth on density and length of blades is shown.

41
139. ZIEMAN, J.C., "Quantitative and Dynamic Aspects of the Ecology of Turtle

Grass, Thalassia testudinwn," Estuarine Research, Vol. 1, Oct. 1973,

pp. 541-562.

Seagrasses bordering the temperate and tropical coastlines are a valuable

resource. Techniques were developed to measure the production and seasonal

dynamics of Thalassia testudinwn. Production of leaf material varied from 0.3

to 10.0 grams dry weight per square meter per day in south Florida. Mean

values were 2.3 to 5.0 grams dry weight per square meter per day. Leaf growth

rates averaged 2 to 5 millimeters per day; maximum values exceeded 10 millimeters per day. The rhizomes of Thalassia were found 5 to 25 centimeters in

the sediment, and roots penetrated 4 to 5 meters. Leaves constituted 15 to 22

percent of the total plant biomass, and leaf standing crops were found from 30

to 650 grams weight per square meter, with average values of 126 and 280 grams

weight per square meter in inshore and offshore waters, respectively. Leaf

densities averaged 3,460 to 4,300 blades per square meter. Thalassia was

found to have an optimum temperature near 300 Celsius and an optimum salinity

near 30 parts per thousand. Standing crop varied by about 50 percent throughout the year. Thalassia produced about 6.8 crops of leaves per year. Few

were directly grazed. The leaves decayed rapidly, losing 65 percent of their

original weight in 7 weeks.

140. ZIEMAN, J.C., "Methods for the Study of the Growth and Production of

Turtle Grass, Thatassia testudinwn Konig," AquacuLture, Vol. 4, No. 2,

Oct. 1974, pp. 139-143.

Measurement of the productivity of vascular hydrophytes by gas exchange

methods is inaccurate due to the storage of gases within the leaves. A method

was developed for the study of turtlegrass (Thalassia testudinum), which

allows (a) the monitoring of the blade populations without disturbing the

plant, and (b) the determination of leaf growth and net production of the

blades, in addition to other biotic variables associated with the growth and

development of the plant. The technique involves the marking of individual

blades with a modified stapler, and the retrieval of the marked blades after a

2- to 3-week interval. The production measured is that which is readily

available as a nutrient source to the consumers of the Thalassia community.

141. ZIEMAN, J.C., "Tropical Seagrass Ecosystems and Pollution," Tropical

Marine Pollution, E.J.F. Wood and R.C. Johannes, eds., Elsevier

Scientific Publishing Go., New York, 1975, pp. 63-74.

This article provides a general discussion of seagrasses, their value to

the coastal ecosystem, and the effect that pollutants and stresses have on

seagrass beds. Halodule, Syringodium, Cymodocea, and Halophila are discussed;

Thalassia testudinwn is emphasized as the species on which most information

has been collected. The adverse effects of dredging and filling, sewage,

changing temperature, and salinity on seagrasses are discussed.

142. ZIEMAN, J.C., "Seasonal Variation of Turtle Grass, Thalassia testudinum

Konig, with Reference to Temperature and Salinity Effects," Aquatic

Botany, Vol. 1, June 1975, pp. 107-124.

Although turtlegrass (Thatassia testudinwn) is a tropical marine plant,

studies show it undergoes seasonal fluctuations. Maximum values of productivity, standing crop, leaf length, blade density, and other biotic variables are reached in the warmer summer months. Thalassia has a temperature

42
optimum near 30* Celsius and a salinity optimum near 30 parts per thousand.

Deviations of these environmental parameters from their optima depress the

biotic viability of the plant. Minimum values for the measured variables were

encountered during periods of seasonally low temperatures or high temperatures

coupled with lowered salinity. Thalassia has a slow response to environmental

stress due to the stored starch reserves in the extensive rhizome system.

143. ZIEMAN, J.C., "The Ecological Effects of Physical Damage from Motor Boats

on Turtle Grass Beds in Southern Florida," Aquatic Botany, Vol. 2, No. 2,

June 1976, pp. 127-139.

Observation has shown that beds of turtlegrass (Thalassia testudinwn),

although highly productive, do not recover rapidly following physical disturbance of the rhizome system. In shallow waters the most common form of rhizome

disturbance (boat damage) is from motorboat propellers.

In turtlegrass beds which are otherwise thriving, tracks resulting from

propellers have been observed to persist from 2 to 5 years. The proportion of

fine sediment components is reduced in the sediments from the boat markings,

and the pH and EH are reduced in comparison to the surrounding grass bed.

This type of damage is most likely to occur in the shallow passes between

islands and keys, areas that are also the slowest to recover due to the rapid

tidal currents present in the shallow passes.

144. ZIEMAN, J.C., BRIDGES, K.W., and McROY, C.P., "Seagrass Literature Survey," Technical Report D-78-4, U.S. Army Engineer Waterways Experiment

Station, Vicksburg, Miss., Jan. 1978.

An extensive review of the published and unpublished literature pertaining to seagrasses, up to mid-1977, was prepared. Broad scientific subject

areas that relate to seagrasses, such as anatomy, ecology, morphology, taxonomy, and physiology, were considered together with more specific factors

such as substrate selectivity, water quality, productivity, colonization,

effect of physical energy (waves, tidal currents, sediment transport), propagation, and tolerance to disturbance. The bibliography has a keyword index

and also includes two appendixes, an author index and a source index, in

microfiche form.

145. ZIMMERMAN, M.C., and LIVINGSTON, R.J., "Effects of Kraft Mill Effluents

on Benthic Macrophyte Assemblages in a Shallow Bay System, Apalachee Bay,

North Florida, USA," Marine Biology, Vol. 34, No. 4, Mar. 1976, pp. 297-

312.

This study determined the impact of kraft-papermill effluents on the offshore benthic macrophyte distribution in a shallow north Florida bay. A polluted river drainage system was compared to an unpolluted one. The affected

area was characterized by elevated levels of color and turbidity. In polluted

areas, red and brown algae were proportionately more abundant than chlorophytes and spermatophytes. Except for areas of acute impact, there was no

significant difference in species diversity between polluted and unpolluted

parts of the bay. The pattern of macrophyte species composition reflected

various water quality parameters. It was postulated that the reduction of

normal dominants, such as Thatassia testudinwn and Halimeda incraseata,

allowed colonization by opportunistic species. Nearshore coastal systems in

Apalachee Bay thus were affected by gradients in water quality in addition to

natural (seasonal) fluctuations in key physical and chemical parameters.

43
IV. KEYWORD INDEX

Keyword Reference Number

Algae 23, 26, 51, 60, 61, 113, 117, 145

Bibliography 47, 54, 74, 98, 144

Blowouts 95

Boat damage 143

Control 81, 127

Cymodocea 30, 31, 37, 44, 48, 141

Decomposition 35, 40, 41, 42

Depth 55, 81 100, 119

Diplanthera 18, 27, 30, 36, 37, 67, 84, 85, 86

Distribution 6, 7, 31, 44, 45, 50, 54, 61, 69, 81, 82, 85,

89, 100, 101, 117, 124, 125

Dredging 6, 21, 29, 30, 84, 109, 141

Ecology 1, 2, 3, 15, 17, 20, 28, 34, 46, 59, 62, 63,

73, 80, 82, 83, 86, 88, 97, 101, 119, 123, 137,

141

Eelgrass 1, 2, 3, 4, 5, 6, 10, 12, 13, 16, 21, 22, 38,

40, 41, 42, 44, 47, 54, 55, 57, 59, 60, 62, 63,

64, 69, 70, 71, 72, 74, 75, 76, 82, 83, 88, 89,

90, 91, 92, 96, 97, 98, 100, 101, 102, 103,

106, 108, 111, 112, 115, 121, 123, 124, 127

Epiphytes 37, 40, 46, 51, 62, 63, 72, 96

Erosion 6, 30, 95, 117

Fertilization 92

Field guide (key) 8, 27, 44, 47, 49, 135

Fish 1, 2, 3, 19, 20, 34, 82

Food chain 1, 2, 3, 16, 18, 20, 23, 34, 40, 48, 62, 103,

105, 119, 121, 137

Fungi 79

Geographical Area

Alaska 12, 69, 70, 71, 77

Bahamas 85, 117

California 10, 13, 55

Canada 41, 60, 127

Caribbean 46, 95, 129

Chesapeake Bay 7, 11, 65, 88, 89, 90, 91, 92, 93, 119

Denmark 115

Florida 15, 18, 19, 20, 24, 39, 51, 52, 56, 78, 79, 81,

83, 85, 86, 87, 99, 109, 113, 114, 120, 128,

134

Griat Britain 111

Gulf of Mexico 26, 29, 30, 31, 32, 34, 35, 37, 39, 50, 52, 56,

61, 67, 109, 110, 129

Mexico 28, 59

Mississippi 29, 31, 32, 5n , 61

New Jersey 38

New York 16, 54

44
I

Keyword Reference Number

North Carolina 1, 2, 3, 78, 96, 122, 124

Pacific Coast 10, 13, 100, 108, 121, 125

Puerto Rico 85

Texas 23, 27, 34, 35, 37, 67, 68, 84, 85, 110

Virginia 6, 7, 11, 63, 65, 88, 90, 91, 92, 93, 119

Washington (Pacific Coast) 100, 108, 121, 125

West Indies 95

Halodule 19, 29, 31, 39, 44, 52, 58, 59, 68, 83, 99,

101, 109, 110 114, 133, 137, 141

Halophila 27, 31, 39, 43, 44, 58, 59, 68, 141

Hormone 56, 106

Hurricane 32, 126

Ice 70

Invertebrates 3, 18, 28, 34, 40, 42, 46, 82, 83, 88, 89, 122,

137

Lagoons 10, 28

Light 10, 25, 58, 68, 102, 106, 125

Macrofauna 15, 88, 137

Manateegrass 19, 30, 31, 39, 52, 58, 59, 67, 68, 76, 106

Milfoil 11

Myriophyllum 11 j

Nutrient cycling 31, 34, 35, 37, 40, 41, 42, 72, 75, 76, 78, 80,

92, 96, 97, 124

Osmoregulation 53

Oyster 127

Photosynthesis 10, 12, 23, 84, 96

Phyllospadix 25, 101

Physical disturbance 90, 91 143

Planting

Cost 9, 13, 21, 130

Methods 4, 5, 9, 13, 16, 19, 21, 29, 30, 56, 57, 65,

102, 103, 104 106, 107, 109, 111, 112, 114,

128, 129, 130, 131, 132, 133

Pollution 80, 141, 145

Predation 18, 89

Productivity 1, 2, 3, 6, 7, 10, 11, 15, 19, 23, 25, 28, 31,

34, 35, 37, 41, 42, 46, 48, 52, 55, 66, 67, 71,

75, 76, 84, 86, 94, 96, 97, 103, 107, 115, 120,

123, 124, 125, 136, 139, 140, 142, 145

Remote sensing 24, 38, 91, 107, 138

Ruppia 6, 8, 14, 19, 27, 28, 33, 37, 39, 58, 66, 68,

85, 92, 101, 114

Salinity 12, 14, 25, 30, 53, 66, 67, 68, 104, 105, 106,

118, 139, 141, 142

Scallop 122

Sediments 21, 29, 35, 54, 57, 64, 93, 95, 116, 117, 119,

133, 134, 143

Seed 5, 87, 100, 128, 132

45
Kewyord Reference Number

Shoalgrass 18, 19, 30, 31, 36, 39, 44, 52, 67, 106, 109,

114

Stabilize sediments 6, 30, 117, 119

Stress 11, 12, 14, 18, 59, 70, 80, 89, 90, 91, 95,

103, 113, 120, 125, 126, 131, 141, 143, 145

Syringodium 18, 19, 39, 44, 48, 52, 58, 59, 67, 68, 76, 95,

133

Taxonomy 7, 8, 27, 33, 39, 43, 44, 45, 47, 49, 50, 53,

61, 87, 99, 107, 108, 110, 135

Temperature 12, 25, 30, 68, 104, 105, 106, 113, 125, 141,

142

Thalassia 9, 15, 18, 19, 27, 30, 31, 36, 37, 39, 44, 46,

47, 51, 52, 53, 56, 58, 59, 68, 76, 78, 79, 80,

83, 84, 85, 86, 87, 94, 95, 106, 114, 117, 120,

125, 126, 128, 129, 130, 131, 132, 133, 138,

139, 140, 141, 142, 143, 145

Turtlegrass 9, 15, 18, 19, 27, 30, 31, 36, 37, 39, 44, 46,

47, 51, 52 53, 56, 58, 59, 68, 76, 78, 79, 80,

83, 84, 85, 86, 87, 94, 95, 106, 114, 117, 120,

125, 126, 128, 129, 130, 131, 132, 133, 138,

139, 140, 141, 142, 143, 145

Urchin 18

Vallisneria 114, 135

Value 6, 26, 48, 73, 103, 105, 116, 118, 119, 121,

122, 123, 125, 134, 141

Waves 134

Widgeongrass (ditchgrass) 6, 14, 19, 28, 33, 37, 39, 58, 66, 68, 92, 101,

106, 135

Zostera 1, 2, 3, 4, 5, 6, 10, 12, 16, 21, 22, 38, 40,

41, 42, 44, 47, 54, 55, 57, 59, 60, 62, 63, 64,

69, 70, 71, 72, 74, 75, 76, 82, 88, 89, 90, 91,

92, 96, 97, 98, 100, 101, 102, 103, 106, 107,

111, 112, 115, 121, 123, 124, 127

46
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