In scattered freshwater brooks and streams the descendents of some of Martha’s Vineyard’s earliest inhabitants can be found. Island native brook trout, a fish of subtle multi-hued beauty, still survive.
That a species so susceptible to environmental change can be found in small streams and brooks owes much to the protection of Island landscapes. Brook trout require clear, cool streams and high water quality.
On a warm summer day last week three technicians from the Division of Fisheries and Wildlife (DFW) traveled to the Vineyard to survey four streams. Their visit was part of a continuing statewide project looking at the fisheries of Massachusetts’s streams and rivers, according to DFW southeast district fisheries manager Steve Hurley.
“We are basically updating biological data for environmental review and for a variety of other purposes,” Mr. Hurley said. “We have been sampling streams using standardized protocol for probably close ten years now.”
Mr. Hurley said the visit last week was needed to fill in some data gaps on Island streams. The men used small packs to generate an electrical charge to temporarily stun fish.
The Division has been involved in identifying waters considered Coldwater Fishery Resources (CFR), according to the DFW website. Identification of CFRs is based on fish samples collected annually by staff biologists and technicians. The identified CFRs are organized geographically by watershed and the information is updated annually. Currently there are nearly 900 streams identified statewide. The CFR lists are useful tools for highlighting environmentally sensitive areas.
Brook trout occupy less than half of their original range in Massachusetts, according to DFW. These results reflect the condition of brook trout across their entire eastern United States range, according to an assessment released by Trout Unlimited and a coalition of state and federal agencies. These beautiful fish historically thrived in rivers and streams stretching from Maine to Georgia. The presence of brook trout in a watershed is considered an indicator that water quality is excellent. Declining brook trout populations can provide an early warning that the health of an entire stream, lake, or river is at risk, say fisheries managers.
The technicians surveyed Paint Mill brook, Tiasquam brook and Mill brook in Chilmark and Blackwater brook in West Tisbury.
They found wild brook trout in three streams. “That was good news,” he said. “Most of them we had known about before, it was just updating the fisheries data.”
In addition to brook trout the men located golden shiner, white perch, American eel and tessellated darter, a small stream fish once called Johnny darters until it was determined that it was a different species.
“They did find in one stream brown bullheads,” he said, “and some American eels.”
The only surprise was the presence of brook trout in a stream where they had not been found in a previous survey. “It was good to see that these wild brook trout are still surviving because they are a cold water species that are very susceptible to changes in the landscape and changes in the climate,” he said. “It was good to see that these wild brook trout populations are still surviving out on Martha’s Vineyard.”
Asked what Islanders could do to protect the trout, Mr. Hurley said buffer zones along the streams and shade are two measures that can protect waterbodies for trout.
“The main thing is to cooperate with the conservation commissions and the other regulatory authorities that regulate the wetlands protection act,” he said. Land protection and water quality are critical factors, he said.
Mr. Hurley said that although the state does stock Island ponds it is likely that descendents of the wild brook trout population survive.
“There are these wild brook trout populations that are still surviving,” Mr. Hurley said. “They were documented as far back as the 1830s by anglers and one of the things to stress is that these are remnant populations, and as long as you protect the landscape you can protect these coldwater streams.”