NOAA Technical Memorandum NMFS-NE-177

Essential Fish Habitat Source Document:

Smooth Skate, Malacoraja senta,

Life History and Habitat Characteristics

U. S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

National Marine Fisheries Service

Northeast Region

Northeast Fisheries Science Center

Woods Hole, Massachusetts

March 2003
155. Food of Northwest Atlantic Fishes and Two Common Species of Squid. By Ray E. Bowman, Charles E. Stillwell, William

L. Michaels, and Marvin D. Grosslein. January 2000. xiv + 138 p., 1 fig., 7 tables, 2 app. NTIS Access. No. PB2000-106735.

156. Proceedings of the Summer Flounder Aging Workshop, 1-2 February 1999, Woods Hole, Massachusetts. By George

R. Bolz, James Patrick Monaghan, Jr., Kathy L. Lang, Randall W. Gregory, and Jay M. Burnett. May 2000. v + 15 p., 5 figs.,

5 tables. NTIS Access. No. PB2000-107403.

157. Contaminant Levels in Muscle of Four Species of Recreational Fish from the New York Bight Apex. By Ashok D.

Deshpande, Andrew F.J. Draxler, Vincent S. Zdanowicz, Mary E. Schrock, Anthony J. Paulson, Thomas W. Finneran, Beth

L. Sharack, Kathy Corbo, Linda Arlen, Elizabeth A. Leimburg, Bruce W. Dockum, Robert A. Pikanowski, Brian May, and

Lisa B. Rosman. June 2000. xxii + 99 p., 6 figs., 80 tables, 3 app., glossary. NTIS Access. No. PB2001-107346.

158. A Framework for Monitoring and Assessing Socioeconomics and Governance of Large Marine Ecosystems. By

Jon G. Sutinen, editor, with contributors (listed alphabetically) Patricia Clay, Christopher L. Dyer, Steven F. Edwards, John

Gates, Tom A. Grigalunas, Timothy Hennessey, Lawrence Juda, Andrew W. Kitts, Philip N. Logan, John J. Poggie, Jr.,

Barbara Pollard Rountree, Scott R. Steinback, Eric M. Thunberg, Harold F. Upton, and John B. Walden. August 2000. v

+ 32 p., 4 figs., 1 table, glossary. NTIS Access. No. PB2001-106847.

159. An Overview and History of the Food Web Dynamics Program of the Northeast Fisheries Science Center, Woods

Hole, Massachusetts. By Jason S. Link and Frank P. Almeida. October 2000. iv + 60 p., 20 figs., 18 tables, 1 app. NTIS

Access. No. PB2001-103996.

160. Measuring Technical Efficiency and Capacity in Fisheries by Data Envelopment Analysis Using the General

Algebraic Modeling System (GAMS): A Workbook. By John B. Walden and James E. Kirkley. October 2000. iii + 15 p.,

9 figs., 5 tables. NTIS Access. No. PB2001-106502.

161. Demersal Fish and American Lobster Diets in the Lower Hudson - Raritan Estuary. By Frank W. Steimle, Robert

A. Pikanowski, Donald G. McMillan, Christine A. Zetlin, and Stuart J. Wilk. November 2000. vii + 106 p., 24 figs., 51 tables.

NTIS Access. No. PB2002-105456.

162. U.S. Atlantic and Gulf of Mexico Marine Mammal Stock Assessments – 2000. Edited by Gordon T. Waring, Janeen

M. Quintal, and Steven L. Swartz, with contributions from (listed alphabetically) Neilo B. Barros, Phillip J. Clapham, Timothy

V.N. Cole, Carol P. Fairfield, Larry J. Hansen, Keith D. Mullin, Daniel K. Odell, Debra L. Palka, Marjorie C. Rossman, U.S.

Fish and Wildlife Service, Randall S. Wells, and Cynthia Yeung. November 2000. ix + 303 p., 43 figs., 55 tables, 3 app. NTIS

Access. No. PB2001-104091.

163. Essential Fish Habitat Source Document: Red Deepsea Crab, Chaceon (Geryon) quinquedens, Life History and

Habitat Characteristics. By Frank W. Steimle, Christine A. Zetlin, and Sukwoo Chang. January 2001. v + 27 p., 8 figs.,

1 table. NTIS Access. No. PB2001-103542.

164. An Overview of the Social and Economic Survey Administered during Round II of the Northeast Multispecies Fishery

Disaster Assistance Program. By Julia Olson and Patricia M. Clay. December 2001. v + 69 p., 3 figs., 18 tables, 2 app.

NTIS Access. No. PB2002-105406.

165. A Baseline Socioeconomic Study of Massachusetts’ Marine Recreational Fisheries. By Ronald J. Salz, David K.

Loomis, Michael R. Ross, and Scott R. Steinback. December 2001. viii + 129 p., 1 fig., 81 tables, 4 app. NTIS Access. No.

PB2002-108348.

166. Report on the Third Northwest Atlantic Herring Acoustic Workshop, University of Maine Darling Marine Center,

Walpole, Maine, March 13-14, 2001. By William L. Michaels, editor and coconvenor, and Philip Yund, coconvenor.

December 2001. iv + 18 p., 14 figs., 2 app. NTIS Access. No. PB2003-101556.

Recent Issues in This Series:
U. S. DEPARTMENT OF COMMERCE

Donald L. Evans, Secretary

National Oceanic and Atmospheric Administration

Vice Admiral Conrad C. Lautenbacher, Jr., USN (ret.), Administrator

National Marine Fisheries Service

William T. Hogarth, Assistant Administrator for Fisheries

Northeast Region

Northeast Fisheries Science Center

Woods Hole, Massachusetts

March 2003

Essential Fish Habitat Source Document:

Smooth Skate, Malacoraja senta,

Life History and Habitat Characteristics

David B. Packer, Christine A. Zetlin, and Joseph J. Vitaliano

National Marine Fisheries Serv., James J. Howard Marine Sciences Lab., 74 Magruder Rd., Highlands, NJ 07732

This series represents a secondary level of scientific publishing. All issues employ

thorough internal scientific review; some issues employ external scientific review.

Reviews are -- by design -- transparent collegial reviews, not anonymous peer

reviews. All issues may be cited in formal scientific communications.

NOAA Technical Memorandum NMFS-NE-177
Editorial Notes on Issues 122-152, 163, and 173-179

in the

NOAA Technical Memorandum NMFS-NE Series

Editorial Production

For Issues 122-152, 163, and 173-179, staff of the Northeast Fisheries Science Center's (NEFSC's) Ecosystems Processes

Division have largely assumed the role of staff of the NEFSC's Editorial Office for technical and copy editing, type

composition, and page layout. Other than the four covers (inside and outside, front and back) and first two preliminary

pages, all preprinting editorial production has been performed by, and all credit for such production rightfully belongs

to, the staff of the Ecosystems Processes Division.

Internet Availability

Issues 122-152, 163, and 173-179 have been copublished, i.e., both as paper copies and as Web postings. All Web postings

are available at: www.nefsc.noaa.gov/nefsc/habitat/efh. Also, all Web postings are in "PDF" format.

Information Updating

By federal regulation, all information specific to Issues 122-152, 163, and 173-179 must be updated at least every five years.

All official updates will appear in the Web postings. Paper copies will be reissued only when and if new information

associated with Issues 122-152, 163, and 173-179 is significant enough to warrant a reprinting of a given issue. All updated

and/or reprinted issues will retain the original issue number, but bear a "Revised (Month Year)" label.

Species Names

The NMFS Northeast Region’s policy on the use of species names in all technical communications is generally to follow

the American Fisheries Society’s lists of scientific and common names for fishes (i.e., Robins et al. 1991a

), mollusks (i.e.,

Turgeon et al. 1998b), and decapod crustaceans (i.e., Williams et al. 1989c), and to follow the Society for Marine

Mammalogy's guidance on scientific and common names for marine mammals (i.e., Rice 1998d

). Exceptions to this policy

occur when there are subsequent compelling revisions in the classifications of species, resulting in changes in the names

of species (e.g., Cooper and Chapleau 1998e

; McEachran and Dunn 1998f).

a

Robins, C.R. (chair); Bailey, R.M.; Bond, C.E.; Brooker, J.R.; Lachner, E.A.; Lea, R.N.; Scott, W.B. 1991. Common and scientific names

of fishes from the United States and Canada. 5th ed. Amer. Fish. Soc. Spec. Publ. 20; 183 p. b

Turgeon, D.D. (chair); Quinn, J.F., Jr.; Bogan, A.E.; Coan, E.V.; Hochberg, F.G.; Lyons, W.G.; Mikkelsen, P.M.; Neves, R.J.; Roper, C.F.E.;

Rosenberg, G.; Roth, B.; Scheltema, A.; Thompson, F.G.; Vecchione, M.; Williams, J.D. 1998. Common and scientific names of aquatic

invertebrates from the United States and Canada: mollusks. 2nd ed. Amer. Fish. Soc. Spec. Publ. 26; 526 p. c

Williams, A.B. (chair); Abele, L.G.; Felder, D.L.; Hobbs, H.H., Jr.; Manning, R.B.; McLaughlin, P.A.; Pérez Farfante, I. 1989. Common

and scientific names of aquatic invertebrates from the United States and Canada: decapod crustaceans. Amer. Fish. Soc. Spec. Publ.

17; 77 p. d

Rice, D.W. 1998. Marine mammals of the world: systematics and distribution. Soc. Mar. Mammal. Spec. Publ. 4; 231 p. e

Cooper, J.A.; Chapleau, F. 1998. Monophyly and interrelationships of the family Pleuronectidae (Pleuronectiformes), with a revised

classification. Fish. Bull. (U.S.) 96:686-726. f

McEachran, J.D.; Dunn, K.A. 1998. Phylogenetic analysis of skates, a morphologically conservative clade of elasmobranchs

(Chondrichthyes: Rajidae). Copeia 1998(2):271-290.
Page iii 

FOREWORD 

One of the greatest long-term threats to the viability of 

commercial and recreational fisheries is the continuing 

loss of marine, estuarine, and other aquatic habitats. 

Magnuson-Stevens Fishery Conservation and 

Management Act (October 11, 1996) 

The long-term viability of living marine resources 

depends on protection of their habitat. 

NMFS Strategic Plan for Fisheries 

Research (February 1998) 

The Magnuson-Stevens Fishery Conservation and 

Management Act (MSFCMA), which was reauthorized 

and amended by the Sustainable Fisheries Act (1996), 

requires the eight regional fishery management councils 

to describe and identify essential fish habitat (EFH) in 

their respective regions, to specify actions to conserve 

and enhance that EFH, and to minimize the adverse 

effects of fishing on EFH. Congress defined EFH as 

“those waters and substrate necessary to fish for 

spawning, breeding, feeding or growth to maturity.” The 

MSFCMA requires NMFS to assist the regional fishery 

management councils in the implementation of EFH in 

their respective fishery management plans. 

NMFS has taken a broad view of habitat as the area 

used by fish throughout their life cycle. Fish use habitat 

for spawning, feeding, nursery, migration, and shelter, but 

most habitats provide only a subset of these functions. 

Fish may change habitats with changes in life history 

stage, seasonal and geographic distributions, abundance, 

and interactions with other species. The type of habitat, 

as well as its attributes and functions, are important for 

sustaining the production of managed species. 

The Northeast Fisheries Science Center compiled the 

available information on the distribution, abundance, and 

habitat requirements for each of the species managed by 

the New England and Mid-Atlantic Fishery Management 

Councils. That information is presented in this series of 

38 EFH species reports (plus one consolidated methods 

report). The EFH species reports are a survey of the 

important literature as well as original analyses of fisheryJAMES J. HOWARD MARINE SCIENCES LABORATORY

HIGHLANDS, NEW JERSEY

SEPTEMBER 1999 

independent data sets from NMFS and several coastal 

states. The species reports are also the source for the 

current EFH designations by the New England and MidAtlantic Fishery Management Councils, and 

understandably have begun to be referred to as the “EFH 

source documents.” 

NMFS provided guidance to the regional fishery 

management councils for identifying and describing EFH 

of their managed species. Consistent with this guidance, 

the species reports present information on current and 

historic stock sizes, geographic range, and the period and 

location of major life history stages. The habitats of 

managed species are described by the physical, chemical, 

and biological components of the ecosystem where the 

species occur. Information on the habitat requirements is 

provided for each life history stage, and it includes, where 

available, habitat and environmental variables that control 

or limit distribution, abundance, growth, reproduction, 

mortality, and productivity. 

Identifying and describing EFH are the first steps in 

the process of protecting, conserving, and enhancing 

essential habitats of the managed species. Ultimately, 

NMFS, the regional fishery management councils, fishing 

participants, Federal and state agencies, and other 

organizations will have to cooperate to achieve the habitat 

goals established by the MSFCMA. 

A historical note: the EFH species reports effectively 

recommence a series of reports published by the NMFS 

Sandy Hook (New Jersey) Laboratory (now formally 

known as the James J. Howard Marine Sciences 

Laboratory) from 1977 to 1982. These reports, which 

were formally labeled as Sandy Hook Laboratory 

Technical Series Reports, but informally known as 

“Sandy Hook Bluebooks,” summarized biological and 

fisheries data for 18 economically important species. The 

fact that the bluebooks continue to be used two decades 

after their publication persuaded us to make their 

successors – the 38 EFH source documents – available to 

the public through publication in the NOAA Technical 

Memorandum NMFS-NE series. 

JEFFREY N. CROSS, (FORMER) CHIEF

ECOSYSTEMS PROCESSES DIVISION

NORTHEAST FISHERIES SCIENCE CENTER
Page iv 
Page v 

Contents 

Introduction ...................................................................................................................................................................................... 1 

Life History ...................................................................................................................................................................................... 1 

Geographical Distribution................................................................................................................................................................. 2 

Habitat Characteristics...................................................................................................................................................................... 3 

Status of the Stocks........................................................................................................................................................................... 4 

Research Needs................................................................................................................................................................................. 4 

Acknowledgments ............................................................................................................................................................................ 5 

References Cited............................................................................................................................................................................... 5 

Tables 

Table 1. Summary of habitat parameters for smooth skate, based on the pertinent literature and most recent NEFSC surveys...7

Figures 

Figure 1. The smooth skate, Malacoraja senta (Garman 1885), male ........................................................................................... 9 

Figure 2. Abundance (% occurrence) of the major prey items of smooth skate collected during NEFSC trawl surveys............. 10 

Figure 3. Distribution of juvenile smooth skate collected during winter NEFSC bottom trawl surveys...................................... 11 

Figure 4. Distribution and abundance of juvenile smooth skate collected during spring NEFSC bottom trawl surveys ............. 12 

Figure 5. Distribution of juvenile smooth skate collected during summer NEFSC bottom trawl surveys ................................... 13 

Figure 6. Distribution and abundance of juvenile smooth skate collected during fall NEFSC bottom trawl surveys .................. 14 

Figure 7. Distribution and abundance of juvenile smooth skate in Massachusetts coastal waters ............................................... 15 

Figure 8. Distribution of adult smooth skate collected during winter NEFSC bottom trawl surveys........................................... 17 

Figure 9. Distribution and abundance of adult smooth skate collected during spring NEFSC bottom trawl surveys .................. 18 

Figure 10. Distribution of adult smooth skate collected during summer NEFSC bottom trawl surveys ........................................ 19 

Figure 11. Distribution and abundance of adult smooth skate collected during fall NEFSC bottom trawl surveys....................... 20 

Figure 12. Spring/fall distributions of juveniles relative to bottom temperature, depth, and salinity based on NEFSC surveys ... 21 

Figure 13. Fall distributions of juveniles relative to bottom temperature and depth based on Massachusetts inshore surveys...... 23 

Figure 14. Spring/fall distributions of adults relative to bottom temperature, depth, and salinity based on NEFSC surveys ........ 24 

Figure 15. NEFSC spring survey index of smooth skate biomass and commercial landings of seven species skate complex....... 26 

Page 1 

INTRODUCTION 

The smooth skate [Malacoraja senta (Garman 1885); 

formerly Raja senta, see McEachran and Dunn (1998); 

Figure 1] occurs along the Atlantic coast of North 

America from the Gulf of St. Lawrence and Labrador 

Shelf to as far south as South Carolina (Bigelow and 

Schroeder 1953; McEachran 1973; McEachran and 

Musick 1975; Kulka et al. 1996). However, it is a boreal 

species whose center of abundance is in the Gulf of 

Maine (McEachran and Musick 1975). 

 McEachran (2002) distinguishes smooth skates from 

other skates in the Gulf of Maine by a combination of the 

following characters: the rostrum is relatively stout and 

extends anterior to anterior-most pectoral rays. The snout 

is only moderately obtuse. The midline of the disc and 

proximal 1/2 to 2/3 of the tail bear an irregular row of 

small thorns. The distal 1/2 to 1/3 of tail of medium to 

large specimens lacks thorns. The dorsal surface is darkcolored without a distinct color pattern. The ventral side 

of disc is uniform white or mostly white with darker 

blotches. Small specimens have two light yellow bands 

on the dorsal side of the tail. 

LIFE HISTORY 

Not much is known about the life history of smooth 

skate. 

 The single fertilized egg is encapsulated in an amber 

to brown case or capsule (Vladykov 1936). The capsules 

are rectangular in shape, 50-61 mm long and 35-46 mm 

wide, and have a strongly convex dorsal surface and a 

nearly flat ventral surface. The anterior horns, which 

curve inward, are about 1/2 the length of the posterior 

horns and the posterior horns are slightly less than the 

length of the capsule exclusive of the horns (McEachran 

2002). The capsules are striated and covered with fibrous 

tendrils. 

 McEachran (2002) reports that smooth skate reaches 

a maximum size of 57.7 cm TL. For their size at maturity, 

using the predictive equations of Frisk et al. (2001) and 

the Northeast Fisheries Science Center (NEFSC) survey 

maximum observed length of 71 cm TL, Lmat is estimated 

at 56 cm TL and Amat is estimated at 5 years (Northeast 

Fisheries Science Center 2000b). 

 Females with fully formed egg capsules are found 

both in summer and winter (McEachran 2002). 

FOOD HABITS 

 Generally, the diet of smooth skate is limited to 

epifaunal crustaceans (McEachran et al. 1976). Decapod 

shrimps and euphausids are the primary food items 

although amphipods and mysids are also important 

(McEachran 1973; McEachran et al. 1976; Bowman et al. 

2000; McEachran 2002). Larger smooth skate also feed 

on small fish (Garrison and Link 2000; see also the 

discussion on the NEFSC food habits database, below). 

 McEachran (1973) studied skates collected from 

Nova Scotia to Cape Hatteras during 1967-1970; the 

following diet description is from him and McEachran et 

al. (1976). 

 On Georges Bank, Pagurus pubescens, 

Dichelopandalus leptocerus, Crangon septemspinosa, 

and Eualus pusiolus were the major decapods eaten, 

while on the Nova Scotian shelf, P. pubescens, Pandulus

spp., and C. septemspinosa were the most numerious 

decapod prey consumed. Meganyctiphanes norvegica was 

the only euphausid eaten, and was eaten more frequently 

during the winter than during the autumn. Monoculodes

sp. was the major amphipod eaten on Georges Bank and 

Dulichia (= Dyopedos) monacantha and Pontogeneia

inermis were the most frequently eaten amphipods eaten 

in the Gulf of Maine and on the Nova Scotian shelf. The 

mysids Erythrops erythrophthalma and Neomysis

americana were also consumed in large numbers. 

 As smooth skate grow, the diet shifts from 

amphipods and mysids to decapods, and euphausids 

appear to be directly correlated to the size of the skate 

(McEachran et al. 1976). Using NEFSC data from 

Georges Bank and the Gulf of Maine from 1977-1980, 

Bowman et al. (2000) reported that that in terms of 

percent weight, the major decapods consumed by skate 

36-51 cm TL included Pandalus borealis and D.

leptocerus. Skate 51-55 cm TL consumed pagurid crabs. 

M. norvegica was eaten by skate 56-60 cm TL, but also 

by skate < 31 cm TL. 

 The 1981-1990 NEFSC food habits database for 

smooth skate [Figure 2; see Reid et al. (1999) for details] 

generally confirms the McEachran (1973) and McEachran 

et al. (1976) studies, even though the sample sizes are 

often quite small. Decapods and crustaceans are the major 

components of the skates’ diet, particularly for skates > 

21 or 31 cm TL. Several fish species are minor, but 

important components of the diet of skates > 31 cm TL. 

Amphipods, which are a major part of the diet of skates 

11-20 cm TL, rapidly decrease in occurrence for larger 

skates. However, there doesn’t seem to be a remarkable 

increase in the occurrence of decapods or euphausids with 

increasing skate size. It is interesting to note though the 

rather high (54%) occurrence of euphausids in the 

stomachs of skates 21-30 cm TL, this may mirror the 

previously mentioned presence of M. norvegica in skate < 

31 cm TL as reported by Bowman et al. (2000).

 The following is a description of the diet from the 

NEFSC food habits database broken down by smooth 

skate size class (Figure 2). 

 For smooth skate 11-20 cm TL, 39% of the diet 

consisted of identifiable amphipods. Identifiable 

euphausids made up 23% of the diet, while pagurid crabs 

and pandalid shrimp, both decapods, together made up 

15% of diet. Identifiable mysids and isopods each made 

up only 8% of the diet. For skate 21-30 cm TL, 54% of 
Page 2 

the diet consisted of identifiable euphausids, and 23% of 

the diet identifiable amphipods. 

 The percent occurrence of identifiable amphipods in 

the diet of smooth skate 31-40 cm TL dropped to 17% 

and identifiable euphausids dropped to 29% of the diet. 

Identifiable decapods made up 21% of the diet; they 

included pagurid crabs, pandalid shrimp, and C. 

septemspinosa. Identifiable fish made up 13% of the diet, 

among which were a yellowtail flounder and a hake. 

Minor prey items included polychaetes (4%) and 

stomatopods (4%). 

 The percent occurrence of identifiable euphausids in 

the diet of skate 41-50 cm TL increased to 38%, while 

identifiable amphipods continued to decrease, down to 

7%. Identifiable decapods, including pandalid shrimp and

C. septemspinosa, made up 21% of the diet. Identifiable 

fish increased to 17% of the diet, species included silver 

hake and witch flounder. 

 The percent occurrence of identifiable euphausids in 

the diet of 51-60 cm TL skate decreased to 32%, while 

identifiable amphipods dropped down to 2%. Identifiable 

decapods, including pagurid crabs, pandalid shrimp, and

C. septemspinosa, increased to 29%. Identifiable fish, 

including silver hake and sand lance, made up 13% of the 

diet. 

 Finally, for smooth skate 61-70 cm TL, identifiable 

euphausids made up 38% of the diet, identifiable pandalid 

shrimp 25% of the diet, identifiable fish 13%, and 

identifiable polychaetes 13%. However, only 7 skate 

stomachs were examined, making any conclusions about 

diet preference for this size class suspect. 

PREDATORS AND SPECIES 

ASSOCIATIONS 

 Not much is known concerning the predators of 

smooth skate, but other skates probably eat them, at least 

as embryos within the egg capsules (McEachran 2002). 

 McEachran and Musick (1975) report that smooth 

and thorny skate (Amblyraja radiata) had a high 

coefficient of associaton during 1967-1970 surveys from 

Nova Scotia to Cape Hatteras, and these two species were 

often negatively associated with little (Leucoraja 

erinacea) and winter (Leucoraja ocellata) skates. They 

consider smooth and thorny skate to be sympatric species. 

 Co-occurrence, and possibly competition with thorny 

skate may have led to food specialization in smooth skate 

and could have caused the low abundance and low 

diversity of prey species in the diet of smooth skate 

(McEachran 1973; McEachran et al. 1976). Thorny skate 

has a diverse diet consisting of both infauna and epifauna 

while smooth skate has a very specialized diet consisting 

largely of epifauna, mostly amphipods, euphausids, 

decapods, and mysids (McEachran 1973; McEachran et 

al. 1976). Thorny skate also feeds on these prey items 

over part of the year, perhaps when the prey are in high 

abundance. Thorny skate is also the more widespread and 

abundant of the two. 

 Using 1973-1997 NEFSC data from Nova Scotia to 

Cape Hatteras, as well as the same NEFSC food habits 

database discussed above, Garrison and Link (2000) 

investigated the dietary guild structure of the fish 

community. Medium (31-60 cm TL) sized smooth skate 

belonged to the “Shrimp/small fish eaters” group, along 

with pollock, redfish, and silver, red, and white hakes. 

The most important prey included euphausiids, pandalid 

shrimps, and various other shrimps as well as fish prey 

such as silver hake, sand lance, and Atlantic herring. 

 Mahon (1997), in surveys of the Scotian Shelf and 

Bay of Fundy from 1970-1993, discovered that smooth 

skate belongs to an assemblage found mainly in the 

eastern Scotian Shelf and also in the mouth of the Bay of 

Fundy. Major species in the assemblage besides smooth 

skate included American plaice, thorny skate, and Vahl’s 

eelpout. 

GEOGRAPHICAL DISTRIBUTION 

 In Canada, smooth skate is distributed around the 

Newfoundland Banks, Labrador Shelf and Grand Banks; 

Kulka et al. (1996) noted a southerly shift in distribution: 

it appeared to be more common on the southern Grand 

Bank during 1991-1994 (collected during 1981-1994). It 

also occurs from the St. Lawrence River estuary, the Gulf 

of St. Lawrence, the Nova Scotian Banks, and the Gulf of 

Maine (Bigelow and Schroeder 1953; McEachran 1973; 

McEachran and Musick 1975; see also Strong and Hanke 

(1995) for the 1970-1993 distribution of smooth skate in 

the Scotia-Fundy region.). McEachran and Musick (1975) 

found it to be fairly abundant on the offshore banks of 

Banquereau, Sable Island, and Western, contrary to 

reports by Bigelow and Schroeder (1953) and Leim and 

Scott (1966). In the Bay of Fundy near Passamaquoddy 

Bay, Macdonald et al. (1984) determined them to be a 

common, regular resident, and within Passamaquoddy 

Bay itself smooth skate increased in abundance during 

summer and declined after late fall. 

 Smooth skate is found throughout the Gulf of Maine, 

its reported center of abundance (Bigelow and Schroeder 

1953; McEachran and Musick 1975; McEachran 2002). 

Bigelow and Schroeder (1953) reported it from the 

southeast slope of Browns Bank, the western side of the 

Gulf, and the offshore Banks, in deep waters near 

Jeffrey’s and Cashes Ledges, and in the basin east and 

southeast of Cape Cod. It has also been found in 

Massachusetts Bay (Collette and Hartel 1988). 

 It occurs on Georges Bank and along the upper slope 

of southern New England, New York, and New Jersey, 

and has been captured off northern Virginia, off 

Chesapeake Bay, and off Charleston, South Carolina 

(Bigelow and Schroeder 1953; McEachran 1973; 

McEachran and Musick 1975; McEachran 2002). 
Page 3 

 McEachran and Musick (1975) reported that there 

are no seasonal trends in abundance. 

JUVENILES 

 NEFSC bottom trawl surveys [see Reid et al. (1999) 

for details] captured juvenile (< 55 cm TL) smooth skate 

mainly in the Gulf of Maine. (Note that winter and 

summer distributions are presented as presence/absence 

data, precluding a discussion of abundances.) In winter, 

concentrations were found near the Northeast Peak 

(Canadian side) of Georges Bank and Northeast Channel 

(Figure 3). In spring they were heavily concentrated in 

the Gulf of Maine (Figure 4). Larger numbers were found 

around the Northeast Channel, the mouth of the Bay of 

Fundy, between German Bank and Lurcher Shoal, east 

and southeast of Cape Cod, and on Jeffreys Ledge. A few 

were found out near the 200 m depth contour on the 

southern flank of Georges Bank down to southern New 

England and even near the Hudson Canyon. In summer 

they were again concentrated mostly in the Gulf of Maine 

(Figure 5). Their distributions in the fall were similar to 

those in the spring (Figure 6). Larger numbers were again 

found around the Northeast Channel, the mouth of the 

Bay of Fundy, and east and southeast of Cape Cod, with a 

few found out near the 200 m depth contour on the 

southern flank of Georges Bank down to southern New 

England and near the Hudson Canyon. 

 Both the spring and fall 1978-2002 Massachusetts 

inshore trawl surveys [see Reid et al. (1999) for details] 

show very small numbers of juveniles around Cape Ann, 

in Massachusetts Bay, and near Cape Cod Bay (Figure 7). 

ADULTS 

 The overall numbers of adult smooth skate (> 56 cm 

TL) captured by the NEFSC bottom trawl surveys were 

much lower than for juveniles. (Again, winter and 

summer distributions are presented as presence/absence 

data, precluding a discussion of abundances.) In winter, 

small concentrations were present in the Gulf of Maine, 

around the 200 m depth contour near the Northeast Peak 

of Georges Bank, around southeast Georges Bank, on 

Georges Bank southeast of Cape Cod (near Cultivator 

Shoal), near Cape Ann, near Crowell Basin in the Gulf, 

and near Long Island (Figure 8). In the spring they were 

scattered throughout the Gulf, near the Northeast Peak 

again and on Georges Bank southeast of Cape Cod, 

around southeast Georges Bank, as well as on the Scotian 

Shelf (Figure 9). In the summer there were small 

concentrations in the Gulf of Maine (Figure 10). 

Distributions in the fall were similar to those in the 

spring, with a number caught around the Northeast Peak 

and southeast of Cape Cod (Figure 11). 

HABITAT CHARACTERISTICS 

 Information on the habitat requirements and 

preferences of smooth skate (based on both the pertinent 

literature and the most recent NEFSC surveys) are 

presented here and summarized in Table 1. 

 Smooth skate has been found at depths from 31-874 

m, but McEachran and Musick (1975) and McEachran 

(2002) considered it most abundant between 110-457 m. 

In the Gulf of Maine, Bigelow and Schroeder (1953) 

reported them to occur throughout the western side of the 

Gulf where water depths are > 73-91 m, 46 m being the 

shallowest and on the offshore Banks as well. Smooth 

skate were also found in the deep trough west of Jeffrey’s 

Ledge, at 146-183 m near Cashes Ledge, and were 

trawled at 91-457 m off southern New England (Bigelow 

and Schroeder 1953). Isolated specimens have been 

captured off Chesapeake Bay at 190 m and off 

Charleston, South Carolina at 874 m (Bigelow and 

Schroeder 1953; McEachran 2002). The spring and fall 

1963-2002 NEFSC trawl surveys from the Gulf of Maine 

to Cape Hatteras (see below) indicated that juveniles 

occurred at depths from 31-500 m with most found > 120 

m (Figure 12), while adults were found between 31-400 

m with most found > 100 m (Figure 14). 

 Bigelow and Schroeder (1953) reported the egg cases 

of smooth skate might have been trawled at depths of 

150-300 m in the St. Lawrence River estuary in July and 

August. Also in Canada, Bigelow and Schroeder (1953) 

reported the occurrence of smooth skate in the Gulf of St. 

Lawrence at 150-326 m, and on La Have and Emerald 

Banks at 91-183 m. Scott (1982a) reported that during 

trawl surveys on the Scotian Shelf in the summers of 

1970-1979, smooth skate were usually caught at depths of 

73-163 m. 

 McEachran and Musick (1975) found smooth skate 

at temperatures from 0.5-4.8EC in the Gulf of St. 

Lawrence, -1.3EC to 11.8EC off northeastern Nova 

Scotia, and 2-10EC from southern Nova Scotia to 

Georges Bank. It was usually caught at 3-8EC on the 

Scotian Shelf during the summers of 1970-1979 (Scott 

1982a). The spring and fall 1963-2002 NEFSC trawl 

surveys from the Gulf of Maine to Cape Hatteras (see 

below) found juvenile smooth skate over a temperature 

range of 2-13EC, with most found between about 4-8EC 

(Figure 12), while adults were found over a temperature 

range of about 3-13EC, with most also found between 

about 4-8EC (Figure 14). 

 Smooth skate is found mostly on soft mud (silt and 

clay) bottoms in deeper areas, but also on sand, broken 

shells, gravel, and pebbles on the offshore banks of the 

Gulf of Maine (Bigelow and Schroeder 1953; McEachran 

and Musick 1975). Scott (1982b) also says that smooth 

skate is restricted to the finer sediments of the Scotian 

Shelf. 

 Scott (1982a) also mentions that on the Scotian Shelf 

during the summers of 1970-1979, smooth skate was 

found at preferred salinities of 32-34 ppt. The spring and 
Page 4 

fall 1963-2002 NEFSC trawl surveys from the Gulf of 

Maine to Cape Hatteras (see below) found juveniles over 

a salinity range of between 32-35 ppt, with most between 

33-34 ppt (Figure 12); adults were found at salinities of 

32-35 ppt, with most between 33-35 ppt (Figure 14). 

JUVENILES 

 The spring and fall distributions of juvenile smooth 

skate relative to bottom water temperature, depth, and 

salinity based on 1963-2002 NEFSC bottom trawl 

surveys from the Gulf of Maine to Cape Hatteras are 

shown in Figure 12. In spring, they were found in waters 

between 2-12EC, with the majority between 4-8EC. Their 

depth range during that season was between 41-400 m 

with most between 121-300 m. Their salinity range was 

between 32-35 ppt, with the majority between 33-34 ppt. 

Juvenile smooth skate were caught over a temperature 

range of 4-13EC during the fall, with most found between 

6-8EC. They were found over a depth range of about 31-

500 m, with most caught at depths between 161-300 m. 

They were found over a salinity range of between 32-35 

ppt, with around 40-50% caught or occurring at 34 ppt. 

The fall 1978-2001 Massachusetts inshore trawl 

surveys found a few juvenile smooth skate at 

temperatures from 5-10EC and at depths from about 36-

75 m (Figure 13). 

ADULTS 

 The spring and fall distributions of adult smooth 

skate relative to bottom water temperature, depth, and 

salinity based on 1963-2002 NEFSC bottom trawl 

surveys from the Gulf of Maine to Cape Hatteras are 

shown in Figure 14. During the spring they were found in 

waters between 3-11EC, with most spread between 4-8EC 

and with a peak at 6EC. They were found at depths 

between 51-400 m, with the majority spread between 

121-400 m. They were found at salinities of between 32-

35 ppt, with a peak at 33 ppt. During the fall, they were 

found over a temperature range of about 4-13EC with a 

few at 16EC and 21EC. Most were found between 6-8EC. 

They were found over a depth range of 31-400 m, with 

most found between approximately 101-400 m. Their 

salinity range was between 32-35 ppt, with the majority 

about evenly spread between 33-35 ppt. 

STATUS OF THE STOCKS 

 The following section is based on Northeast Fisheries 

Science Center (2000a, b). 

 The principal commercial fishing method used to 

catch all seven species of skates [smooth, little, barndoor 

(Dipturus laevis), winter, thorny, clearnose (Raja

eglanteria), rosette (Leucoraja garmani)] is otter 

trawling. Skates are frequently taken as bycatch during 

groundfish trawling and scallop dredge operations and 

discarded recreational and foreign landings are currently 

insignificant, at < 1% of the total fishery landings. 

 Skates have been reported in New England fishery 

landings since the late 1800s. However, commercial 

fishery landings, primarily from off Rhode Island, never 

exceeded several hundred metric tons until the advent of 

distant-water fleets during the 1960s. Landings are not 

reported by species, with over 99% of the landings 

reported as "unclassified skates." Skate landings reached 

9,500 mt in 1969, but declined quickly during the 1970s, 

falling to 800 mt in 1981 (Figure 15). Landings have 

since increased substantially, partially in response to 

increased demand for lobster bait, and more significantly, 

to the increased export market for skate wings. Wings are 

taken from winter and thorny skates, the two species 

currently used for human consumption. Bait landings are 

presumed to be primarily from little skate, based on areas 

fished and known species distribution patterns. Landings 

for all skates increased to 12,900 mt in 1993 and then 

declined somewhat to 7,200 mt in 1995. Landings have 

increased again since 1995, and the 1998 reported 

commercial landings of 17,000 mt were the highest on 

record (Figure 15). 

 The biomass for the seven skate species is at a 

medium level of abundance. For the aggregate complex, 

the NEFSC spring survey index of biomass was relatively 

constant from 1968-1980, then increased significantly to 

peak levels in the mid- to late 1980s. The index of skate 

complex biomass then declined steadily until 1994, but 

has recently increased again. The large increase in skate 

biomass in the mid- to late 1980s was dominated by little 

and winter skate. The recent increase in aggregate skate 

biomass has been due to an increase in small sized skates 

(< 100 cm max. length: little, clearnose, rosette, and 

smooth), primarily little skate. The abundance of smooth 

skate was highest during the early 1970s (Figure 15). 

Smooth skate was, until recently, considered to be 

overfished (Northeast Fisheries Science Center 2000a, b), 

but its status has recently been changed so that it is no 

longer considered to be in an overfished condition 

(NMFS 2002). 

RESEARCH NEEDS 

 Imprecise reporting of fishery statistics where several 

skate species are lumped together under one category 

(e.g., "unclassified skates" or "skates spp.") can mask 

basic changes in community structure and profound 

reduction in populations of larger, slower growing species 

(Dulvy et al. 2000; Musick et al. 2000). Thus, it is 

important to have fishery-independent data on skates 

where the individual species are reported. 

 Northeast Fisheries Science Center (2000b) also 

suggests the following research needs: 
Page 5 

• More life history studies (including age, growth, 

maturity, and fecundity studies) are necessary. 

• Studies of stock structure are needed to identify unit 

stocks. 

• Explore possible stock-recruit relationships by 

examination of NEFSC survey data. 

• Investigate trophic interactions between skate species 

in the complex, and between skates and other 

groundfish. 

• Investigate the influence of annual changes in water 

temperature or other environmental factors on shifts 

in the range and distribution of the species in the 

skate complex, and establish the bathymetric 

distribution of the species in the complex in the 

northwest Atlantic. 

• Investigate historical NEFSC survey data from the 

R/V Albatross III during 1948-1962 when they 

become available, as they may provide valuable 

historical context for long-term trends in skate 

biomass. 

ACKNOWLEDGMENTS 

 The authors thank Barry Shafer, John McCarthy, 

Tom Finneran, and Annette Kalbach for producing the 

maps and graphics. Thanks also to Claire Steimle and 

Judy Berrien for literature reviews and interlibrary loans. 

Frank Almeida and Kathy Sosebee of the NEFSC Woods 

Hole provided much needed information, input, and 

reviews. 

REFERENCES CITED 

Bigelow, H.B. and W.C. Schroeder. 1953. Fishes of the 

Gulf of Maine. U.S. Fish Wildl. Serv., Fish. Bull. 53. 

577 p. 

Bowman, R.E., C.E. Stillwell, W.L. Michaels, and M.D. 

Grosslein. 2000. Food of Northwest Atlantic fishes 

and two common species of squid. NOAA Tech. 

Mem. NMFS-NE-155. 138 p. 

Collette, B.B. and K.E. Hartel. 1988. Annotated list of 

fishes of Massachusetts Bay. NOAA Tech. Mem. 

NMFS-F/NEC-51. 70 p. 

Dulvy, N.K., J.D. Metcalfe, J. Glanville, M.G. Pawson, 

and J.D. Reynolds. 2000. Fishery stability, local 

extinctions, and shifts in community structure in 

skates. Conserv. Biol. 14: 283-293. 

Frisk, M.G., T.J. Miller, and M.J. Fogarty. 2001. 

Estimation and analysis of biological parameters in 

elasmobranch fishes: a comparative life history study. 

Can. J. Fish. Aquat. Sci. 58: 969-981. 

Garrison, L.P. and J.S. Link. 2000. Dietary guild structure 

of the fish community in the Northeast United States 

continental shelf ecosystem. Mar. Ecol. Prog. Ser. 

202: 231-240. 

Kulka, D.W., E.M. DeBlois, and D.B. Atkinson. 1996. 

Non-traditional groundfish species on Labrador Shelf 

and Grand Banks -- skate. DFO Atl. Fish. Res. Doc. 

96/98. 29 p. 

Leim, A.H. and W.B. Scott. 1966. Fishes of the Atlantic 

coast of Canada. Bull. Fish. Res. Board. Can. 155. 

485 p. 

Macdonald, J.S., M.J. Dadswell, R.G. Appy, G.D. 

Melvin, and D.A. Methven. 1984. Fishes, fish 

assemblages, and their seasonal movements in the 

lower Bay of Fundy and Passamaquoddy Bay, 

Canada. Fish. Bull. (U.S.) 82: 121-139. 

Mahon, R. 1997. Demersal fish assemblages from the 

Scotian Shelf and Bay of Fundy, based on trawl 

survey data (1970-1993). Can. Manuscr. Rep. Fish. 

Aquat. Sci. 2426. 38 p. 

McEachran, J.D. 1973. Biology of seven species of skates 

(Pisces: Rajidae). Ph.D. dissertation, Coll. William 

and Mary, Williamsburg, VA. 127 p. 

McEachran, J.D. 2002. Skates. Family Rajidae. In B.B. 

Collette and G. Klein-MacPhee eds. Bigelow and 

Schroeder’s fishes of the Gulf of Maine. 3rd Edition. 

p. 60-75. Smithsonian Institution Press, Washington, 

DC. 748 p. 

McEachran, J.D., D.F. Boesch, and J.A. Musick. 1976. 

Food division within two sympatric species-pairs of 

skates (Pisces: Rajidae). Mar. Biol. 35: 301-317. 

McEachran, J.D. and K.A. Dunn. 1998. Phylogenetic 

analysis of skates, a morphologically conservative 

clade of elasmobranchs (Chondrichthyes: Rajidae). 

Copeia 1998 (2): 271-290. 

McEachran, J.D. and J.A. Musick. 1975. Distribution and 

relative abundance of seven species of skates (Pisces: 

Rajidae) which occur between Nova Scotia and Cape 

Hatteras. Fish. Bull. (U.S.) 73: 110-136. 

Musick, J.A., G. Burgess, G. Cailliet, M. Camhi, and S. 

Fordham. 2000. Management of sharks and their 

relatives (Elasmobranchii). Fisheries 25: 9-13. 

NMFS. 2002. Annual report to Congress on the status of 

U.S. fisheries — 2001. U.S. Dep. Commerce, NOAA, 

NMFS, Silver Spring, MD. 142 p. 

Northeast Fisheries Science Center. 2000a. Report of the 

30th Northeast Regional Stock Assessment 

Workshop (30th SAW): Public Review Workshop. 

Northeast Fish. Sci. Cent. Ref. Doc. 00-04. 53 p. 

Northeast Fisheries Science Center. 2000b. Report of the 

30th Northeast Regional Stock Assessment 

Workshop (30th SAW): Stock Assessment Review 

Committee (SARC) consensus summary of 

assessments. Northeast Fish. Sci. Cent. Ref. Doc. 00-

03. 477 p. 

Reid, R., F. Almeida, and C. Zetlin. 1999. Essential fish 

habitat source document: Fishery independent 

surveys, data sources, and methods. NOAA Tech. 

Mem. NMFS-NE-122. 40 p. 

Scott, J.S. 1982a. Depth, temperature and salinity 

preferences of common fishes of the Scotian Shelf. J. 

Northwest Atl. Fish. Sci. 3: 29-39. 
Page 6 

Scott, J.S. 1982b. Selection of bottom type by 

groundfishes of the Scotian Shelf. J. Fish. Res. Board 

Can. 39: 943-947. 

Scott, W.B. and M.G. Scott. 1988. Atlantic fishes of 

Canada. Can. Bull. Fish. Aquat. Sci. 219. 731 p. 

Strong, M. and A. Hanke. 1995. Diversity of finfish 

species in the Scotia-Fundy region. Can. Tech. Rep. 

Fish. Aquat. Sci. 2017. 106 p. 

Vladykov, V.D. 1936. Capsules d'oeufs de raies de 

l'Atlantique Canadien appartenant au genre Raja. 

Natur. Can. 63: 211-231. 
Page 7 

Table 1. Summary of habitat parameters for smooth skate, based on the pertinent literature and the most recent NEFSC 

surveys. 

Life Stage Depth Substrate Salinity Temperature 

Eggs 1

Egg cases may have been trawled 

at depths of 150-300 m in the St. 

Lawrence River estuary in July 

and August. 

 

Juveniles 2

Found at depths from 31-874 m, 

most abundant between 110-457 

m. In the Gulf of Maine occurs 

throughout western side of the 

Gulf where water depths are > 

73-91 m, 46 m being the 

shallowest and on the offshore 

Banks as well. Also found in the 

deep trough west of Jeffrey’s 

Ledge, at 146-183 m near Cashes 

Ledge, and at 91-457 m off 

southern New England. Isolated 

specimens taken off Chesapeake 

Bay at 190 m and off Charleston, 

South Carolina at 874 m. 

Spring/fall 1963-2002 NEFSC 

trawl surveys from Gulf of Maine 

to Cape Hatteras indicated 

juveniles occurred at depths from 

31-500 m with most found > 120 

m. In Canada: Gulf of St. 

Lawrence at 150-326 m, and on 

La Have and Emerald Banks at 

91-183 m. During trawl surveys 

on the Scotian Shelf in the 

summers of 1970-1979, smooth 

skate usually caught at 73-163 m. 

Fall 1978-2001 Massachusetts 

inshore trawl surveys found a few 

juvenile smooth skate at depths 

from about 36-75 m. 

Found mostly on 

soft mud (silt and 

clay) bottoms in 

deeper areas, but 

also on sand, 

broken shells, 

gravel, and 

pebbles on the 

offshore banks of 

the Gulf of Maine. 

Also restricted to 

the finer sediments 

of the Scotian 

Shelf. 

On the Scotian 

Shelf during the 

summers of 1970-

1979, smooth skate 

was found at 

preferred salinities 

of 32-34 ppt. 

Spring/fall 1963-

2002 NEFSC trawl 

surveys from Gulf 

of Maine to Cape 

Hatteras found 

juveniles over a 

salinity range of 

between 32-35 ppt, 

with most between 

33-34 ppt.

Found at 

temperatures from 

0.5-4.8EC in Gulf of 

St. Lawrence, -1.3EC 

to 11.8EC off 

northeastern Nova 

Scotia, 2-10EC from 

southern Nova Scotia 

to Georges Bank. 

Caught at 3-8EC on 

the Scotian Shelf 

during the summers 

of 1970-1979. 

Spring/fall 1963-

2002 NEFSC trawl 

surveys from Gulf of 

Maine to Cape 

Hatteras found 

juveniles over a 

temperature range of 

2-13EC, with most 

found between about 

4-8EC. Fall 1978-

2001 Massachusetts 

inshore trawl surveys 

found a few juvenile 

smooth skate at 

temperatures from 5-

10EC. 

Adults 3

Same as for juveniles. 

Spring/fall 1963-2002 NEFSC 

trawl surveys from Gulf of Maine 

to Cape Hatteras indicated adults 

were found between 31-400 m 

with most found > 100 m. 

Same as for 

juveniles. 

Same as for 

juveniles. 

Spring/fall 1963-

2002 NEFSC trawl 

surveys from Gulf 

of Maine to Cape 

Hatteras found 

adults at salinities 

of between 32-35 

ppt; most between 

33-35 ppt. 

Same as for juveniles. 

Spring/fall 1963-

2002 NEFSC trawl 

surveys from Gulf of 

Maine to Cape 

Hatteras found adults 

over a temperature 

range of about 3-

13EC; most found 

between about 4-8EC. 

1 Bigelow and Schroeder (1953).

2 Bigelow and Schroeder (1953); McEachran and Musick (1975); Scott (1982a, b); McEachran (2002); 1978-2001 

Massachusetts inshore trawl surveys; 1963-2002 NEFSC trawl surveys. 

3 Bigelow and Schroeder (1953); McEachran and Musick (1975); Scott (1982a, b); McEachran (2002); 1963-2002 

NEFSC trawl surveys. 
Page 8 

Table 1. cont’d. 

Life Stage Prey Predators/Species Associations 

Eggs1

N/A Other skates probably eat them, at least as 

embryos within the egg capsules. 

Juveniles 2

Diet limited to epifaunal crustaceans. 

Decapod shrimps and euphausids are 

primary food items although amphipods 

and mysids are also important. Decapod 

prey include: Pagurus pubescens, 

Dichelopandalus leptocerus, Crangon

septemspinosa, Eualus pusiolus, Pandulus

spp. Euphausids: Meganyctiphanes

norvegica. Amphipods: Monoculodes sp., 

Dulichia (= Dyopedos) monacantha, 

Pontogeneia inermis. Mysids: Erythrops

erythrophthalma, Neomysis americana. 

Minor prey items include fish (yellowtail 

flounder, silver hake, witch flounder, sand 

lance), polychaetes, stomatopods. 

As smooth skate grow, diet shifts from 

amphipods and mysids to decapods; 

euphausids appear to be directly correlated 

to size of the skate. Surveys from 1977-

1980 on Georges Bank and Gulf of Maine 

showed that major decapods consumed by 

skate 36-51 cm TL included Pandalus

borealis and D. leptocerus. Skate 51-55 cm 

TL consumed pagurid crabs. M. norvegica

was eaten by skate 56-60 cm TL, but also 

by skate < 31 cm TL. 1981-1990 NEFSC 

food habits database for smooth skate also 

showed decapods and crustaceans are the 

major components of the skates’ diet, 

particularly for skates > 21 or 31 cm TL. 

Several fish species are minor, but 

important components of the diet of skates 

> 31 cm TL. Amphipods, which are a major 

part of the diet of skates 11-20 cm TL, 

rapidly decrease in occurrence for larger 

skates. However, there’s no real increase in 

the occurrence of decapods or euphausids 

with increasing skate size. 

Smooth and thorny skate (Amblyraja 

radiata) have a high coefficient of 

associaton; these two species often 

negatively associated with little (Leucoraja 

erinacea) and winter (Leucoraja ocellata) 

skates. Smooth and thorny skate are 

sympatric species. 

Co-occurrence, and possibly competition 

with thorny skate may have led to food 

specialization in smooth skate and could 

have caused the low abundance and low 

diversity of prey species in the diet of 

smooth skate. Thorny skate has a diverse diet 

consisting of both infauna and epifauna 

while smooth skate has a very specialized 

diet consisting largely of epifauna. 

Using 1973-1997 NEFSC data from Nova 

Scotia to Cape Hatteras and NEFSC food 

habits database, medium (31-60 cm TL) 

sized smooth skate belonged to the 

“Shrimp/small fish eaters” group, along with 

pollock, redfish, and silver, red, and white 

hakes. The most important prey included 

euphausiids, pandalid shrimps, and various 

other shrimps as well as fish prey such as 

silver hake, sand lance, and Atlantic herring. 

Based on surveys of the Scotian Shelf and 

Bay of Fundy, smooth skate belongs to an 

assemblage found mainly in the eastern 

Scotian Shelf and also in the mouth of the 

Bay of Fundy. Major species in the 

assemblage besides smooth skate included 

American plaice, thorny skate, and Vahl’s 

eelpout. 

Adults 3

Same as for juveniles; however, note that 

larger skates may consume more decapods 

and euphausids as well as fish rather than 

amphipods and mysids. 

Same as for juveniles. 

1

 McEachran (2002). 

2 McEachran (1973); McEachran and Musick (1975); McEachran et al. (1976); Mahon (1997); Bowman et al. (2000); 

Garrison and Link (2000); McEachran (2002); NEFSC 1973-1990 food habits database. 3 McEachran (1973); McEachran and Musick (1975); McEachran et al. (1976); Mahon (1997); Bowman et al. (2000); 

Garrison and Link (2000); McEachran (2002); NEFSC 1973-1990 food habits database. 
Page 9 

Figure 1. The smooth skate, Malacoraja senta (Garman 1885), male, from Scott and Scott (1988).
Page 10 

Figure 2. Abundance (% occurrence) of the major prey items of smooth skate collected during NEFSC bottom trawl 

surveys from 1981-1990 [see Reid et al. (1999) for details]. 

Euphausiidae 23.1%

Amphipoda 23.1%

Paguridae 7.7%

Pandalidae 7.7 %

Gammaridea 15.4%

Crustacea 7.7%

Isopoda 7.7%

Mysidacea 7.7%

11-20 cm 

n = 12

Euphausiidae 53.8%

Crustacea 23.1%

Amphipoda 15.4%

Gammaridea 7.7%

21-30 cm 

n = 11

Euphausiidae 29.2%

Amphipoda 16.7%

Polychaeta 4.2%

Fish 12.5 %

Decapoda 20.8%

Crustacea shrimp 12.5%

Stomatopoda 4.2%

31-40 cm 

n = 19

Amphipoda 7.1%

Crustacea 11.9%

Polychaeta 2.4%

Fish 16.7 %

Decapoda 21.4%

Stomatopoda 2.4%

Euphausiidae 38.1%

41-50 cm 

n = 31

Amphipoda 1.6%

Crustacea shrimp 25.4%

Fish 12.7 %

Euphausiidae 31.7%

Decapoda 28.6 %

51-60 cm 

n = 55

Crustacea 12.5%

Polychaeta 12.5%

Fish 12.5 %

Euphausiidae 37.5%

Pandalidae 25.0 %

61-70 cm 

n = 7
Page 11 

Smooth Skate

NEFSC Bottom Trawl Surveys

(1964 - 2002)

Number per tow Winter/juveniles

(<= 55 cm)

Present

Figure 3. Distribution of juvenile smooth skate collected during winter NEFSC bottom trawl surveys [1964-2002, all 

years combined; see Reid et al. (1999) for details]. Survey stations where juveniles were not found are not shown. 
Page 12 

Smooth Skate

NEFSC Bottom Trawl Surveys

(1968 - 2002)

Spring/juveniles

(<= 55 cm)

NPTOW

1 - 10

11 - 100

101 - 1000

> 1000

Number per tow

Figure 4. Distribution and abundance of juvenile smooth skate collected during spring NEFSC bottom trawl surveys 

[1968-2002, all years combined; see Reid et al. (1999) for details].
Page 13 

Smooth Skate

NEFSC Bottom Trawl Surveys

(1963 - 1995)

Number per tow

Summer/juveniles

 (<= 55 cm)

Present

Figure 5. Distribution of juvenile smooth skate collected during summer NEFSC bottom trawl surveys [1963-1995, all 

years combined; see Reid et al. (1999) for details]. Survey stations where juveniles were not found are not shown.
Page 14 

Smooth Skate

NEFSC Bottom Trawl Surveys

(1963 - 2001)

Fall/juveniles

(<= 55 cm)

NPTOW

1 - 10

11 - 100

101 - 1000

> 1000

Number per tow

Figure 6. Distribution and abundance of juvenile smooth skate collected during fall NEFSC bottom trawl surveys [1963-

2001, all years combined; see Reid et al. (1999) for details]. 
Page 15 

New Hampshire

Cape Ann

Massachusetts

Cape Cod

Martha's

Vineyard

Nantucket

Spring/juveniles

NPTOW

1 - 10

Smooth Skate

Massachusetts Inshore

Trawl Survey

(1978 - 2002)

Spring/juveniles

(<= 55 cm)

 Number per tow

Figure 7. Distribution and abundance of juvenile smooth skate in Massachusetts coastal waters collected during the 

spring and autumn Massachusetts inshore trawl surveys [1978-2002, all years combined; see Reid et al. (1999) for 

details].
Page 16 

New Hampshire

Cape Ann

Massachusetts

Cape Cod

Martha's

Vineyard

Nantucket

Spring/juveniles

NPTOW

1 - 10

Smooth Skate

Massachusetts Inshore

Trawl Survey

(1978 - 2001)

Fall/juveniles

(<= 55 cm)

 Number per tow

Figure 7. cont’d. 
Page 17 

Smooth Skate

NEFSC Bottom Trawl Surveys

(1964 - 2002)

Number per tow

Winter/adults

 (> 55 cm)

Present

Figure 8. Distribution of adult smooth skate collected during winter NEFSC bottom trawl surveys [1964-2002, all years 

combined; see Reid et al. (1999) for details]. Survey stations where adults were not found are not shown. 
Page 18 

Smooth Skate

NEFSC Bottom Trawl Surveys

(1968 - 2002)

Spring/adults

(> 55 cm)

NPTOW

1 - 10

11 - 100

101 - 1000

> 1000

Number per tow

Figure 9. Distribution and abundance of adult smooth skate collected during spring NEFSC bottom trawl surveys [1968-

2002, all years combined; see Reid et al. (1999) for details].
Page 19 

Smooth Skate

NEFSC Bottom Trawl Surveys

(1963 - 1995)

Number per tow

Summer/adults

 (> 55 cm)

Present

Figure 10. Distribution of adult smooth skate collected during summer NEFSC bottom trawl surveys [1963-1995, all 

years combined; see Reid et al. (1999) for details]. Survey stations where adults were not found are not shown.
Page 20 

Smooth Skate

NEFSC Bottom Trawl Surveys

(1963 - 2001)

Fall/adults

(> 55 cm)

NPTOW

1 - 10

11 - 100

101 - 1000

> 1000

Number per tow

Figure 11. Distribution and abundance of adult smooth skate collected during fall NEFSC bottom trawl surveys [1963-

2001, all years combined; see Reid et al. (1999) for details]. 
Page 21 

0

5

10

15

20

25

30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Bottom Temperature (°C)

Percent

Trawls N=10537

Occurrence N=725

Catch N=1685

0

5

10

15

20

25

30

1-10

11-2021-3031-4041-5051-6061-7071-8081-90

91-100

101-120121-140141-160161-180181-200201-300301-400401-500

Bottom Depth (m)

Percent

Trawls N=12193

Occurrence N=843

Catch N=1958

0

20

40

60

26 27 28 29 30 31 32 33 34 35 36 37

Salinity (PPT)

Percent

Trawls N=1959

Occurrence N=110

Catch N=316

Smooth Skate

NEFSC Bottom Trawl Survey 

Spring/Juveniles

Figure 12. Spring and fall distributions of juvenile smooth skate and trawls relative to bottom water temperature, depth, 

and salinity based on NEFSC bottom trawl surveys (1963-2002; all years combined). White bars give the distribution of 

all the trawls, black bars give the distribution of all trawls in which smooth skate occurred, and gray bars represent, 

within each interval, the percentage of the total number of smooth skate caught. 
Page 22 

0

5

10

15

20

25

30

2 4 6 8 10 12 14 16 18 20 22 24 26 28

Bottom Temperature (°C)

Percent

Trawls N=11844

Occurrence N=772

Catch N=1606

0

5

10

15

20

25

30

1-10

11-2021-3031-4041-5051-6061-7071-8081-90

91-100

101-120121-140141-160161-180181-200201-300301-400401-500

>500

Bottom Depth (m)

Percent

Trawls N=13543

Occurrence N=874

Catch N=1817

0

20

40

60

27 29 30 31 32 33 34 35 36 37

Salinity (PPT)

Percent

Trawls N=1956

Occurrence N=116

Catch N=246

Smooth Skate

NEFSC Bottom Trawl Survey 

Fall/Juveniles 

Figure 12. cont’d. 
Page 23 

0

10

20

30

40

50

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

Bottom Temperature (°C)

Percent

Trawls N=2067

Occurrence N=10

Catch N=28

0

10

20

30

40

1-5

6-10

11-1516-2021-2526-3031-3536-4041-4546-5051-5556-6061-6566-7071-7576-8081-85

Bottom Depth (m)

Percent

Trawls N=2156

Occurrence N=10

Catch N=28

Smooth Skate

Massachusetts Inshore Trawl Survey 

Fall/Juveniles 

Figure 13. Fall distributions of juvenile smooth skate and trawls relative to bottom water temperature and depth based on 

Massachusetts inshore trawl surveys (1978-2001, all years combined). White bars give the distribution of all the trawls, 

black bars give the distribution of all trawls in which smooth skate occurred, and gray bars represent, within each 

interval, the percentage of the total number of smooth skate caught. 
Page 24 

0

10

20

30

40

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Bottom Temperature (°C)

Percent

Trawls N=10537

Occurrence N=203

Catch N=276

0

5

10

15

20

25

1-10

11-2021-3031-4041-5051-6061-7071-8081-90

91-100

101-120121-140141-160161-180181-200201-300301-400401-500

Bottom Depth (m)

Percent

Trawls N=12193

Occurrence N=244

Catch N=345

0

20

40

60

26 27 28 29 30 31 32 33 34 35 36 37

Salinity (PPT)

Percent

Trawls N=1959

Occurrence N=20

Catch N=26

Smooth Skate

NEFSC Bottom Trawl Survey 

Spring/Adults 

Figure 14. Spring and fall distributions of adult smooth skate and trawls relative to bottom water temperature, depth, and 

salinity based on NEFSC bottom trawl surveys (1963-2002; all years combined). White bars give the distribution of all 

the trawls, black bars give the distribution of all trawls in which smooth skate occurred, and gray bars represent, within 

each interval, the percentage of the total number of smooth skate caught. 
Page 25 

0

5

10

15

20

25

30

2 4 6 8 10 12 14 16 18 20 22 24 26 28

Bottom Temperature (°C)

Percent

Trawls N=11844

Occurrence N=241

Catch N=330

0

5

10

15

20

1-10

11-2021-3031-4041-5051-6061-7071-8081-90

91-100

101-120121-140141-160161-180181-200201-300301-400401-500

>500

Bottom Depth (m)

Percent

Trawls N=13543

Occurrence N=280

Catch N=396

0

10

20

30

40

27 29 30 31 32 33 34 35 36 37

Salinity (PPT)

Percent

Trawls N=1956

Occurrence N=32

Catch N=46

Smooth Skate

NEFSC Bottom Trawl Survey 

Fall/Adults

Figure 14. cont’d. 
Page 26 

Figure 15. NEFSC spring survey index of smooth skate biomass and commercial landings of the seven species skate 

complex from the Gulf of Maine to the Mid-Atlantic Bight. 

Gulf of Maine, Georges Bank, Southern New England, Mid-Atlantic Bight

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

196019621964196619681970197219741976197819801982198419861988199019921994199619982000

Year

Landings (metric tons)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Stratified Mean Weight/Tow (kg)

Skate complex, commercial landings (mt)

Survey index of smooth skate biomass
Publishing in NOAA Technical Memorandum NMFS-NE

Jon A. Gibson, Biological Sciences Editor & Laura S. Garner, Editor

Manuscript Qualification

This series represents a secondary level of scientific publishing in the National Marine Fisheries Service (NMFS). For all

issues, the series employs thorough internal scientific review, but

not necessarily external scientific review. For most issues, the

series employs rigorous technical and copy editing. Manuscripts

that may warrant a primary level of scientific publishing should

be initially submitted to one of NMFS’s primary series (i.e.,

Fishery Bulletin, NOAA Technical Report NMFS, or Marine

Fisheries Review).

Identical, or fundamentally identical, manuscripts should

not be concurrently submitted to this and any other publication

series. Manuscripts which have been rejected by any primary

series strictly because of geographic or temporal limitations may

be submitted to this series.

Manuscripts by Northeast Fisheries Science Center (NEFSC)

authors will be published in this series upon approval by the

NEFSC's Deputy Science & Research Director. Manuscripts by

non-NEFSC authors may be published in this series if: 1) the

manuscript serves the NEFSC’s mission; 2) the manuscript meets

the Deputy Science & Research Director’s approval; and 3) the

author arranges for the printing and binding funds to be transferred

to the NEFSC’s Research Communications Unit account from

another federal account. For all manuscripts submitted by nonNEFSC authors and published in this series, the NEFSC will

disavow all responsibility for the manuscripts’ contents; authors

must accept such responsibility.

The ethics of scientific research and scientific publishing are

a serious matter. All manuscripts submitted to this series are

expected to adhere -- at a minimum -- to the ethical guidelines

contained in Chapter 1 (“Ethical Conduct in Authorship and

Publication”) of the CBE Style Manual, fifth edition (Chicago, IL:

Council of Biology Editors). Copies of the manual are available

at virtually all scientific libraries.

Manuscript Preparation

Organization: Manuscripts must have an abstract, table

of contents, and -- if applicable -- lists of tables, figures, and

acronyms. As much as possible, use traditional scientific manuscript organization for sections: “Introduction,” “Study Area,”

“Methods & Materials,” “Results,” “Discussion” and/or “Conclusions,” “Acknowledgments,” and “References Cited.”

Style: All NEFSC publication and report series are obligated to conform to the style contained in the most recent edition

of the United States Government Printing Office Style Manual.

That style manual is silent on many aspects of scientific manuscripts. NEFSC publication and report series rely more on the

CBE Style Manual, fifth edition.

For in-text citations, use the name-date system. A special

effort should be made to ensure that the list of cited works contains

all necessary bibliographic information. For abbreviating serial

titles in such lists, use the most recent edition of the BIOSIS Serial

Sources (Philadelphia, PA: Biosciences Information Service).

Personal communications must include date of contact and full

name and mailing address of source.

For spelling of scientific and common names of fishes,

mollusks, and decapod crustaceans from the United States and

Canada, use Special Publications No. 20 (fishes), 26 (mollusks),

and 17 (decapod crustaceans) of the American Fisheries Society

(Bethesda, MD). For spelling of scientific and common names

of marine mammals, use Special Publication No. 4 of the Society

for Marine Mammalogy (Lawrence, KS). For spelling in general,

use the most recent edition of Webster’s Third New International

Dictionary of the English Language Unabridged (Springfield,

MA: G.&C. Merriam).

Typing text, tables, and figure captions: Text, tables, and

figure captions must be converted to the NOAA-wide standard

of WordPerfect. In general, keep text simple (e.g., don’t switch

fonts and type sizes, don’t use hard returns within paragraphs,

don’t indent except to begin paragraphs). Also, don't use the

WordPerfect automatic footnoting function; all notes should be

indicated in the text by simple numerical superscripts, and listed

together in an "Endnotes" section prior to the "References Cited"

section. Especially, don’t use the WordPerfect graphics function

for embedding tables and figures in text.

Tables may be prepared either with WordPerfect text or with

the WordPerfect table formatting function. If text is used, then

data should be assigned to columns by using all tabs or all spaces,

but not a combination of the two.

Each figure should be supplied both on paper and on disk,

unless there is no digital file of a given figure. Except under

extraordinary circumstances, color will not be used in illustrations.

Manuscript Submission

Authors must submit one paper copy of the double-spaced

manuscript, one disk copy, and original figures (if applicable).

NEFSC authors must include a completely signed-off “NEFSC

Manuscript/Abstract/Webpage Review Form.” Non-NEFSC

authors who are not federal employees will be required to sign a

“Release of Copyright” form.

Send all materials and address all correspondence to:

Jon A. Gibson (Biological Sciences Editor)

NMFS Northeast Fisheries Science Center

166 Water Street

Woods Hole, MA 02543-1026 USA.

NORTHEAST FISHERIES SCIENCE CENTER

Dr. John G. Boreman, Acting Science & Research Director

Capt. John T. Moakley, Operations, Management & Information Services Chief

Teri L. Frady, Research Communications Chief
Research Communications Unit

Northeast Fisheries Science Center

National Marine Fisheries Service, NOAA

166 Water St.

Woods Hole, MA 02543-1026

Publications and Reports

of the

Northeast Fisheries Science Center

MEDIA

 MAIL

The mission of NOAA's National Marine Fisheries Service (NMFS) is "stewardship of living marine resources for the benefit of the

nation through their science-based conservation and management and promotion of the health of their environment." As the research

arm of the NMFS's Northeast Region, the Northeast Fisheries Science Center (NEFSC) supports the NMFS mission by "planning,

developing, and managing multidisciplinary programs of basic and applied research to: 1) better understand the living marine resources

(including marine mammals) of the Northwest Atlantic, and the environmental quality essential for their existence and continued

productivity; and 2) describe and provide to management, industry, and the public, options for the utilization and conservation of living

marine resources and maintenance of environmental quality which are consistent with national and regional goals and needs, and with

international commitments." Results of NEFSC research are largely reported in primary scientific media (e.g., anonymously-peerreviewed scientific journals). However, to assist itself in providing data, information, and advice to its constituents, the NEFSC

occasionally releases its results in its own media. Those media are in four categories:

Northeast Fisheries Science Center Reference Document -- This series is issued irregularly. The series typically includes: data

reports on field and lab observations or experiments; progress reports on continuing experiments, monitoring, and assessments;

manuals describing routine surveying and sampling programs; background papers for, and summary reports of, scientific meetings;

and simple bibliographies. Issues receive internal scientific review, but no technical or copy editing.

Fishermen's Report -- This information report is a quick-turnaround report on the distribution and relative abundance of

commercial fisheries resources as derived from each of the NEFSC's periodic research vessel surveys of the Northeast's continental

shelf. There is no scientific review, nor any technical or copy editing, of this report.

OBTAINING A COPY: To obtain a copy of a NOAA Technical Memorandum NMFS-NE or a Northeast Fisheries Science

Center Reference Document, or to subscribe to the Fishermen's Report or the The Shark Tagger, either contact the NEFSC

Editorial Office (166 Water St., Woods Hole, MA 02543-1026; 508-495-2228) or consult the NEFSC webpage on "Reports

and Publications" (http://www.nefsc.noaa.gov/nefsc/publications/).

ANY USE OF TRADE OR BRAND NAMES IN ANY NEFSC PUBLICATION OR REPORT DOES NOT IMPLY

ENDORSEMENT.

NOAA Technical Memorandum NMFS-NE -- This series is issued irregularly. The series typically includes: data reports of

long-term or large-area studies; synthesis reports for major resources or habitats; analytical reports of environmental conditions

or phenomena; annual reports of assessment or monitoring programs; manuals describing unprecedented field and lab techniques;

literature surveys of major resource or habitat topics; proceedings and collected papers of scientific meetings; and indexed and/

or annotated bibliographies. All issues receive internal scientific review and most issues receive technical and copy editing.

The Shark Tagger -- This newsletter is an annual summary of tagging and recapture data on large pelagic sharks as derived from

the NMFS's Cooperative Shark Tagging Program; it also presents information on the biology (movement, growth, reproduction,

etc.) of these sharks as subsequently derived from the tagging and recapture data. There is internal scientific review, but no technical

or copy editing, of this newsletter.