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Chapter 6 - Diadromous FishImportant Marine Areas for AmericanShadSpring: Chesapeake, Delaware and Hudson riversand adjacent coastal watersFall: Northern Gulf of MaineAmerican EelAmerican eel occurs throughout the coastal drainages, upto hundreds of miles inland, as well as in all estuaries inthe region (Figure 6-7). The Northwest Atlantic regionrepresents a relatively small portion of the global range,from the St. Lawrence River, Canada to Venezuela. Thisspecies is greatly diminished at the northern limit of itsrange in Canada; no data are available from the southernlimit of the range.There are too few records of American eel in the NOAAtrawl surveys to interpret. Adult eels presumably migratequickly through this geography on their way to theSargasso Sea and thus have low probability of being detectedin a trawl survey. The listing finding (USFWS2007) summarized available information on ocean distributionof larval (leptocephali) and silver eels. The majorityof leptocephali enter the Florida Current just southof Cape Hatteras directly from the Sargasso Sea. Theremainder may enter the Florida Current by a more southernroute. Other than this likely current transport, littleis known. Similarly, actual distances, routes, and depths ofmigration for adult eels are unknown.Important Marine Areas for American EelNot enough data to determineAtlantic SalmonLong Island Sound and the Connecticut River are thesouthern limit of the range of Atlantic salmon in theUnited States (Figure 6-8). Salmon in New Englandrivers outside Maine (Connecticut, Pawcatuck,Merrimack) were extirpated and recovery efforts continuethrough stocking and passage improvements. Wild salmonstill exist in the Gulf of Maine (Penobscot, Kennebec andeight eastern Maine rivers) and Bay of Fundy. A widespreadcollapse in Atlantic salmon abundance startedaround 1990. In the past decade, United States salmonreturns across all rivers have averaged 1,600 fish; returnsin 2005 were 1,320 fish. All stocks are extremely small,with only the Penobscot River population at a viable level.Most populations are still dependent on hatcheryproduction and current marine survival regimes arecompromising the long-term prospects of even thesehatchery-supplemented populations (Kocik and Sheehan2006).For this Assessment, marine distribution of Atlanticsalmon could not be mapped with NOAA data, but adultsare known to congregate in the waters off Greenland andmigrate to spawning rivers from the Connecticut Rivernorthward (NMFS USFWS 2005). Post smolt surveyshave also tracked movements in coastal waters (Kocik andSheehan 2006).Important Marine Areas for AtlanticSalmonNot enough data to determineAtlantic SturgeonAtlantic sturgeon spawning populations occur in eachsub-section of the region, but in only a handful of largerivers, e.g., Kennebec, Hudson, and Delaware Rivers(Atlantic Sturgeon Status Review Team 2007). Mostwatersheds where they occur (Figure 6-9) host onlywandering juveniles, although occasionally in substantialnumbers. All rivers and estuaries where they occurrepresent important habitat.Some fishery-dependent data are available regardingAtlantic sturgeon habitat use. A 2007 ASMFC reportshows concentrations of sturgeon bycatch in shallow watersin a few locations including Massachusetts Bay, off theeast shore of Cape Cod, Rhode Island coastal waters, NewYork Bight, and the Delmarva Peninsula. The authorsnote that seasonal trends were confounded with fisherybehavior, e.g. type of net used, but the data provides a usefulindication of the locations and types of coastal habitatsused by sturgeon.6-12Northwest Atlantic Marine Ecoregional Assessment • Phase 1 Report