SECTION 4: Management Measures

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4.3. HABITAT ASSESSMENT

Management Measure Description

The construction of a marina in any waterbody

can disrupt aquatic habitats. This management

measure is important because of the value of

protecting natural habitats so they continue to

provide food and recreational opportunities for

people, as well as food and shelter for plants and

animals, and so their roles in the ecological health

of waterbodies are protected. Past waterfront

development has adversely affected many

waterbodies, but our knowledge of ecology has

increased. We now realize the importance of

healthy aquatic habitats to both our health and the

overall health of our waterbodies. Efforts to

decrease the introduction of invasive and exotic

species have increased, and minimizing pollution in

waterbodies is widely accepted as a sound

ecological and economic practice. In many cases,

federal and state laws require analyses of the

potential impacts on the natural environment

before projects begin. This management measure

focuses on marina siting and design and extends

to assessments of how marinas can incorporate

natural habitats into their siting and design.

When well designed and cared for, marinas can

be a valuable habitat for plants and animals that

are adapted to quiet, sheltered waters. Regardless

of the type of waterbody on which a marina is to

be constructed, siting it where its development or

operation will diminish the biological or economic

value of the surrounding habitats should be very

carefully considered, especially if the potential site

is near locations that have been given special

designations by local, state, or federal governments. Such habitats might be fish spawning

areas, shellfish harvesting areas, designated

wetlands, beds of submerged aquatic vegetation

(SAV), or areas where threatened or endangered

species are known to occur. If a marina is

properly designed and located, aquatic plants and

animals should be able to continue to use the

marina waters for the same activities (e.g.,

reproduction or feeding) that occurred in the

waters before the marina’s presence.

Marinas that have been operating for a while can

provide sheltered, quiet waters for plants and

animals that prefer this type of environment or for

animals that need this type of environment during

specific life stages, such as spawning. Where the

surrounding environment has been developed and

offers little in the way of natural habitat, such as

in an urbanized waterfront district, a marina might

provide a refuge for many species. A pollution

prevention and control program, based on the

management measures presented in this guidance,

can help maintain or improve water and habitat

quality for aquatic species.

The locations of all important aquatic and riparian

habitats in a locality or waterbody might not be

known. A visual survey by a biologist may be

appropriate before any marina construction or

expansion begins, and a specialist in aquatic

habitat restoration can be contacted if marina

management is considering modifying the marina

to create good aquatic habitat in the marina basin.

Geographic information systems (GIS) are being

used increasingly to map biological resources in

many states and show promise as a method of

conveying important habitat and other siting information to marina developers and environmental

Management Measure for Habitat Assessment:

Site and design marinas to protect against adverse effects on shellfish resources, wetlands, submerged aquatic vegetation, or other important riparian

and aquatic habitat areas as designed by local, state, or federal governments.
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protection agencies. The state department of

environmental protection or natural resources can

be contacted for this type of information.

Applicability

This management measure is applicable to new

and expanding marinas where site changes might

affect wetlands, shellfish beds, aquatic vegetation,

or other important aquatic resources or habitats.

Best Management Practices

♦ Conduct habitat surveys and characterize

the marina site, including identifying any

exotic or invasive species.

The first step in constructing a marina that will be

compatible with the surrounding natural environment or expanding or modifying an existing

marina to create a more natural environment is to

characterize the environment of the proposed site

or operational marina. Before marina development or expansion, critical or unique habitats, such

as beds of submerged vegetation and shellfish

beds, should be identified. The importance of the

area that will be affected by development to

aquatic organisms for spawning, feeding, or their

overall survival should be assessed within the

context of the entire waterbody (Figure 4-6).

Equally as important, exotic plants and animals

that could be problematic for marina operation

should be identified. Table 4-1 lists some common

exotic and invasive aquatic species in the United

States. Once the site has been characterized,

marina development or expansion can proceed in

a way that minimizes adverse effects on aquatic

life and habitats.

♦ Assess habitat function (e.g., spawning

area, nursery area, feeding area) to minimize indirect effects.

An area proposed for marina development or

expansion could be used seasonally by fish or

other animals. Animals use special areas of

many coves, shorelines, beds of submerged

vegetation, rivers, streams, and estuaries for

short periods of time—from a few nights to

weeks—for particular life functions such as

migration, spawning, and rearing young. Marinas can accommodate these special, short-term

uses if marina designers and managers are

aware of the need for the areas and the marina is

built with the needs in mind.

♦ Use rapid bioassessment techniques to

assess effects on biological resources.

Rapid bioassessment techniques, where they have

been developed, provide cost-effective biological

assessments of potential marina development

sites. Rapid bioassessment uses biological criteria

(usually invertebrate and fish populations) as

indicators of the condition of a habitat. To apply

rapid bioassessment to a marina development site

or an operating marina, select biological communities at the proposed site or the operational marina

are compared to the same biological communities

at an undisturbed site in the same waterbody or a

similar one. The biological health of the proposed

site or marina basin is rated based on how

favorably the invertebrate or fish communities

there compare with those of the undisturbed site.

Scores from rapid bioassessments are useful for

determining whether a site is stressed by pollution

or other factors, such as habitat alteration. Rapid

bioassessment protocols for macroinvertebrates

and fish in freshwater streams and rivers are

being developed by many states, and a document

on them is available from EPA at the web address

Figure 4-6. Habitat assessment was used at Elliot

Bay Marina (Washington) to design the marina to

work with natural habitat function. Wide openings

between rock groin-type breakwaters, docks, and

beach give easy access to migrating juvenile

salmon leaving Puget Sound, while providing good

water circulation and tidal changes inside the

marina basin. A man-made 1,500-foot-long sandy

beach has replaced lost habitat, providing a

feeding ground for young salmon. Schools of

young salmon and herring move throughout the

marina basin (USEPA, 1996: Clean Marinas—

Clear Value).
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Table 4-1. Common Invasive and Exotic Species of the United States
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<http://www.epa.gov/owowwtr1/monitoring/rbp/

index.html>.

♦ Redevelop waterfront sites that have been

previously disturbed and expand existing

marinas.

Waterfront areas that have been previously used

for industrial or military purposes might make

good locations for new marinas because they

have been developed before, usually have all the

necessary infrastructure, and minimize disturbances to aquatic habitats. Many sites suitable for

recreational boating facilities may be located in

existing urban harbors where shorelines have

been modified by bulkheading and filling. The

adverse environmental consequences of redevelopment are usually minimal, and redevelopment

can improve water quality, expand upland habitats,

beautify and expand shorelines, and provide

additional public access.

Waterfronts that are converted from waterdependent uses, such as marinas and recreational

boating, to non-water-dependent uses, such as

residences, office space, and shopping areas,

reduce the availability of sites for marina development. To protect against such conversion in areas

that contain important habitat, a state may purchase the property or the development rights from

existing water-dependent uses. To preserve an

existing marina, for example, a state government

could pay the difference between the market

value for other non-water-dependent development, such as for condominiums, and the waterdependent value of the marina to the marina

owner, and receive in return a guarantee that the

site would not be converted to a non-waterdependent use. States can use this method to

retain sites suitable for marinas, maintain access

for boating uses of the waterways, prevent

conversion to other uses, and reduce the base

value for property taxes.

♦ Consider alternative sites where adverse

environmental effects will be minimized or

positive effects will be maximized.

An analysis of alternative sites (sites other than

the one proposed) can be used to demonstrate

which site is the most economically and environmentally suitable. Analysis of alternative sites and

designs has been effectively used to reduce the

effects of development (including effects on

tidelands, stream courses, shorelines, wetlands,

and submerged aquatic vegetation) at many

proposed marinas, and to find sites with flushing

characteristics better than those at the sites

initially proposed.

Many marinas built on freshwater lakes and rivers

over the past two decades are located on what

are known as brownfields, or shoreland that had

been modified and seriously abused by previous

industrial facilities. Usually, these areas support

little to no natural vegetation or habitats when

they are first converted to marinas. The marinas

have turned these areas into recreational sites and

public access points and have provided sheltered

areas with protected shorelines, where natural

vegetation has been able to reestablish itself.

♦ Create new habitats or expand habitats in

the marina basin.

Almost any surface placed in coastal or inland

waters, and especially rough surfaces—including

rocks, piles, piers, and floats—quickly becomes

home to a host of plants, animals, and bacteria.

The submerged parts of breakwaters, piers, and

floating docks are excellent examples of this kind

of “created” habitat. The plants that colonize

these surfaces provide refuge for a variety of

invertebrates and are a good source of food for

juvenile fish, which in turn can attract sport fish

(Figure 4-7).

♦ Minimize disturbance of riparian areas.

Riparian areas are the narrow areas along the

banks of rivers, streams, lakes, ponds, reservoirs,

The Hammond Marina (Indiana) was

built on a derelict brownfield industrial

site with a steel mill slag shoreline. The

area is now a pleasant and protected

boating facility with an attractive public

access area, and it is popular as a

sportfishing site. The local economy

has benefitted from the redevelopment,

and shorelines, upland habitats, and

aquatic habitat at the site have been

tremendously improved (USEPA, 1996:

Clean Marinas —Clear Value).
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and wetlands. They may be vegetated, or may be

beaches or rocky areas. Vegetated riparian areas

extract nutrients from runoff from the land as it

moves toward the waterbody and from the water

that constantly circulates along the banks of the

waterbody. The nutrients make them very productive habitats, with biodiversity and biomass

typically higher than those of adjacent uplands.

Many processes important to the health of

waterbodies occur in vegetated riparian areas,

including the following:

• Large quantities of nutrients are absorbed as

waters pass through riparian areas.

• Eroded soils and other pollutants are filtered

out of the water and absorbed by riparian

vegetation.

• Nutrients are modified from forms that can’t

be used by aquatic organisms to forms they

can readily use.

• The vegetation in riparian areas serves as a

refuge for species for nesting, hiding from

predators, and foraging.

Beaches and rocky shorelines also provide habitat

variety and are important to many aquatic organisms. Because of the importance of all types of

riparian areas to the general health of

waterbodies, minimizing disturbances to them

during marina development can be beneficial.

Creating favorable conditions for the presence of

riparian or wetland areas within a marina basin

might be an effective, low-cost way to improve

water quality in the basin or increase habitat

diversity in the basin, depending on site conditions

and space limitations.

♦ Use dry stack storage.

An alternative to building new docks for expanding boating access and marina capacity is to build

dry stack storage facilities, in which many boats

are stored on vertical stands on very little land.

Boats stored in dry stack storage do not leak

antifoulants to the water and can be more easily

maintained on land in protected hull maintenance

areas, providing less opportunity for spillage

directly to surface waters. Dry stack storage has

minimal environmental effects, and where zoning

restrictions permit it, it is an appropriate means to

increase public access to waterways.

BMP Summary Table 3 summarizes the BMPs for

Habitat Assessment mentioned in this guidance.

Figure 4-7. Oak Harbor Marina sign. Oak Harbor

Marina (Washington) has used its marina waters to

raise salmon for release. Volunteers built salmon

pens, and more than 420,000 salmon have been

released as a result of the program. Deep River

Marina (Connecticut) was the site for a 3-year

federal/state stocking program for Atlantic salmon.

The Puerto Rico Department of Natural Resources’

Fisheries Office is located in Puerto del Rey Marina

(Puerto Rico) and uses part of the facility’s clean

waters for an injured sea turtle rescue and recovery

program (USEPA, 1996; Clean Marinas–Clear

Value).
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