Distribution and Abundance of Fishes and Invertebrates in North Atlantic Estuaries 



Introduction 



Rationale 



This report presents information on the spatial and 

 temporal distribution, relative abundance, and life his- 

 tory characteristics of 58 species of fishes and inverte- 

 brates (Table 1 ) in 1 7 estuaries in Massachusetts, New 

 Hampshire, and Maine. Its purpose is to disseminate 

 data developed from the National Oceanic and Atmo- 

 spheric Administration's (NOAA) Estuarine Living Ma- 

 rine Resources (ELMR) program (see inside front 

 cover). The ELMR program is conducted by the Bio- 

 geographic Characterization Branch of the Strategic 

 Environmental Assessments (SEA) Division. The pri- 

 mary data compiled include the presence, distribution, 

 and relative abundance of each species and the time 

 period it utilizes each estuary. The data and framework 

 presented are illustrative of the nationwide ELMR 

 program (Monaco et al. 1990, Nelson et al. 1991, 

 Nelson 1992, Stone et al. 1994). 



The objective of the ELMR program is to develop a 

 consistent data base on the presence, distribution, 

 relative abundance, and life history characteristics of 

 ecologically and economically important fishes and 

 invertebrates in the nation's estuaries. The data base 

 is divided into five study regions (Figure 1) and con- 

 tains the monthly relative abundance of each species' 

 life stage by estuary for three salinity zones (seawater, 

 mixing, and tidal fresh) identified in NOAA's National 

 Estuarine Inventory (NEI) Data Atlas-Volume I and 

 supplement (NOAA 1985). The nationwide data base 

 contains information for 1 35 fish and invertebrate spe- 

 cies found in 122 estuaries. 



Estuaries are among the most productive natural sys- 

 tems and have been shown to be important nursery 

 areas that provide food, refuge from predation, and 

 valuable habitat for many species (Tyler 1971, 

 MacDonald et al. 1 984, Langton et al. 1 989, Day et al. 

 1 989, Ayvazian et al. 1 992). Estuarine organisms that 

 support important commercial and recreational fisher- 

 ies include bivalves, decapods, and a variety of finfish. 

 In spite of the well-documented importance of estuar- 

 ies to fishes and invertebrates, few consistent and 

 comprehensive data bases exist that allow examina- 

 tions of the relationships between estuarine species 

 found in or among groups of estuaries. Furthermore, 

 much of the distribution and abundance information for 

 estuarine-dependent species (i.e., species that require 

 estuaries during their life cycle) is for offshore life 

 stages and does not adequately describe estuarine 

 distributions (NOAA 1990, Darnell et al. 1983). 



Only a few sampling programs (e.g., Massachusetts 

 Division of Marine Fisheries, Maine Department of 

 Marine Resources inshore trawl surveys) collect fishes 

 and invertebrates with identical methods across groups 

 of estuaries within a region (Howe et al. 1 991 , MDMR 

 1993). Therefore, most existing estuarine fisheries 

 data cannot be compared among estuaries because of 

 the variable sampling strategies. In addition, existing 

 research programs do not focus on how groups of 

 estuaries may be important for regional fishery man- 

 agement, and few compile information for species 

 having little or no economic value. 



Figure 1 . ELMR study regions and regional research institutions. 



NOAA NMFS, 

 Hammond, OR 



West Coast 



32 estuaries 

 47 species 



North Atlantic 



17 estuaries, 58 species 



DMR, Boothbay Harbor. ME 

 UNH, Durham. NH 

 UMASS, Amherst, MA 



Mid Atlantic 



22 estuaries. 61 species 



NOAA SEA Division, 

 Silver Spring. MD 



VIMS, Gloucester Point. VA 



NOAA NMFS, Beaufort. NC 



Southeast Atlantic 



20 estuaries, 40 species 



