Tuesday, April 23, 2013

The Amazing Freshwater Eel

Globally, there are 16 species of freshwater eel, and they spawn in each of the world’s oceans. The freshwater eel is what we call a catadromous fish, a fish that spends its life in rivers and streams, eventually returning to the sea to spawn and die. This lifecycle is the opposite of anadromous fish, like the familiar river herring which travels up rivers to reproduce and return to the ocean. It is believed that the American eel, Rhode Island’s resident species, spawns in the Sargasso Sea, although no one has ever witnessed this event. In fact, very little is known about this mysterious animal. A PBS Nature documentary was aired last week and provides a fascinating look at these fish.

Populations of eel around the world are at an all-time low, due to the prevalence of dams on our rivers, mortality in hydro turbines, overfishing, and many other environmental challenges. Glass eels and elvers, the tiny young eels that return to rivers in the spring, are currently harvested in Maine and South Carolina. The huge price paid for these eels has made poaching a problem, and has made those who can legally fish for them rich. The elvers, no bigger than your little finger, are sold to fish farms in China and Japan where they are raised to adulthood and sold. Japan alone consumes 130,000 tons of eel each year. This photo, taken by Tim Watts, shows a congregation of elvers at the first dam on the Weweantic River in Massachusetts.

American eel have been minimally managed as a fishery in the United States. An adult female can lay up to 4 million eggs which develop through several life stages and drift slowly back toward coastal rivers. There are few restrictions on commercial harvest of adult eels other than a six inch size restriction, and the recreational limit is 50 eels per day per person with a six inch size limit. A limited elver fishery is still open.

There are many proposed recommendations to help the American eel, including seasonal closures, prohibiting traps and eel pots by recreational fishermen, closing the elver fishery and habitat protections such as dam removal.

The Atlantic States Marine Fisheries Commission has developed an Interstate Fishery Management Plan and has written several addenda to this plan. They are currently holding hearings in Atlantic coast states to gather public comment on Draft Addendum III. The plan proposes increased monitoring by the states and recommendations to improve American eel habitat, as well as recommendations to reduce mortality. Comments are due May 2nd. To comment, click on American Eel under Managed Species on their website.

Friday, April 12, 2013

Spring fish runs are off to a great start

The annual fish run is off to a great start this spring, and fish are being monitored by volunteers throughout the watershed. On the Ten Mile River, over two thousand fish had been netted by this week and lifted over the dam at Omega Pond. A fish count is being conducted this year at Hunts Mill where the fish ladder is now complete.

Fish are also being lifted over the Saugatucket River dam on Main Street in Wakefield. This site has a poorly designed fish ladder, and fish often get caught below the dam. DEM uses this spot to fill their truck and bring fish to both Indian Lake, which is the headwaters of the Saugatucket River, and to Worden's Pond, the headwaters of the Pawcatuck River. Fish will be able to use a new ladder at Horseshoe Falls on the Pawcatuck this year, and with the addition of a fishway at Kenyon Mill, by next year they will be able to reach Worden's Pond.

On the Mill River in Taunton, fish have been spotted above the Hopewell Mills dam for the first time in over 200 years. This dam was removed last fall and is the first in a series of three dam removals on the Mill River. Because this is a large restoration project, the Massachusetts Division of Marine Fisheries has installed a video monitoring station on the river to better understand the population of this run and what fish are using the river. This bar rack directs the fish past the video monitor. It is apparent now that there has been a small surviving run of fish, because several hundred herring have been counted, as have many yellow perch and white suckers which also migrate upstream to spawn. We are very excited to see the fish return to the Bay, and love to get reports from dedicated volunteers and partners who work hard on river restoration projects.