Fish (Freshwater Osteichthyes)

Fish: Freshwater Osteichthyes             

Following their appearance roughly 410 million years ago, bony fish were able to adapt to freshwater environments as well as marine ones (though it appears certain the first fish evolved in salt water). Of the 36 fish species listed, which have been found in fresh or brackish waters on the island, 10 are native species confined to fresh water. Ten native species that can occur in either fresh or brackish water have been recorded, nine are primarily native marine species also known from brackish waters, and seven are species (including one hybrid) of fresh-water “game” fish that have been introduced at one time or another. The Massachusetts Division of Fisheries and Wildlife has maintained an active trout stocking program for decades in several island ponds. Saltwater and brackish water species recorded below are known only from major ponds or bays, which are either permanently or periodically connected to salt water, usually by intentional openings or those made by storms. The information below was collected over the last 85 years. 

The major ponds on Nomans Land Island National Wildlife Refuge were man-made about 1915-1920 by the then-owner of the island, which is why they have no native fish other than American Eels (Anguilla rostrata). A trout of unknown species was once introduced into one or more of the larger ponds on Nomans Land Island but has now been extirpated. One species of brackish water fish has been observed in a small shore-side pond there, but its identity is unknown.  

The excellent paper by MacKenzie and Andrews (1997) describes the origins of the several types of ponds on the Vineyard, some beginning as kettle holes and others as river and stream beds created by water flowing from the base of the melting ice sheet. These authors describe how the major ponds along the south shore started out as shallow salt-water bays and then became separated from the ocean by barrier sand bars about 4,500 years ago, becoming increasingly fresh water over time. They also describe how the native fishes probably colonized the part of the Coastal Plain that became the island as the ice sheet retreated northward. Before the ocean rose to its present level and while most of the continental shelf was still exposed, there were more and larger rivers and lakes present than there are today, and it was thus easier for these fish to spread to areas from which they had been forced out by the ice sheet. When the ice reached its greatest extent, nearly all the continental shelf was exposed because the sea level was about 300 feet lower than today. At this time, zoogeographers believe that the native fish species that later colonized the part of the continental shelf, which is the island today, were confined to one or two refugia. One was probably on the continental shelf east of where the Carolinas are now and another smaller one may have been where George’s Bank is today (Hartel et al. 2002). In any case, it is clear that our native freshwater species and many native brackish water species primarily arrived here by colonization from the south and were then trapped here as the sea rose to surround the island about 5,000 years ago. It also seems certain that our native fish did not all arrive at the same time. Those most tolerant of the cold probably came first. And vegetarians had to arrive before those species that prey on them, such as pickerel and yellow perch, could survive here. 

Whenever any of the larger south shore ponds are opened to the sea for an extended period, either by natural means such as hurricanes or intentionally, significant numbers of salt-water species regularly enter from the ocean. An extensive survey of Tisbury Great Pond after such a period in October and November, 1906 (Kendall, 1906) revealed 85 species of fish of which only 20 were the expected fresh and brackish water species listed below. The 65 others were all species typically found only in salt water.

As pointed out by Hartel et al. (2002:206), the general zoogeographical affinities of the fresh and brackish water fish known from the island are southern. Species such as Redfin Pickerel and Banded Sunfish are found only as far north as the current Coastal Plain of Massachusetts, indicating southern origin. However, a few species may have originally reached part of the early post-glacial Coastal Plain, part of which is now the island, from a refugium located where George’s Bank is today. Variation in some northern forms of Mummichog, Rainwater Killifish, and Inland Silverside suggest this possibility. In general, for the Commonwealth as a whole, there are nearly twice as many native species known south of Cape Cod than there are known north of it, a pattern very similar to that for marine bony fishes.

By far the most authoritative and current publication on Massachusetts fresh-water fish is Hartel et al. (2002) which provides much more detailed distributional information and which is also the source of the taxonomic sequence used here. We’re grateful for information from Dr. Caleb Slater, a fisheries biologist with the Massachusetts Division of Fisheries and Wildlife hatchery system, for information on current stocking activity on the Vineyard.

 As a postscript, it should be mentioned that there are a total of 98 fresh water and coastal ponds on the island which cover nearly 9,000 acres, an area approximately equivalent to 15% of the island’s land area. Unfortunately, several of these are showing signs of degradation (Martha’s Vineyard Commission fact sheet). Included on this list are some of the larger ponds such as Edgartown Great Pond, Lagoon Pond, Poucha Pond, Squibnocket Pond, Tisbury Great Pond, and Lower Chilmark Pond. Farm Pond, Sengekontacket Pond and Lake Tashmoo have also been impacted. The future health of local fish populations will depend on whether efforts to reverse the trend toward more deterioration will be made and will be successful. 

Other publications on the island’s marine fish consulted for this section are Smith (1899), Culbert and Raleigh (2001), Whitworth (1996), Schmidt (1986), and Elvin (1966), which has interesting commentary on changes in historical abundance. 

Allan Keith; edited by Matt Pelikan, June 2, 2023