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The Issue of Bycatch
September 01, 2006
On The Water
When fishermen catch non-targeted organisms, those fish, mammals, seabirds, or turtles are referred to as bycatch. If they are returned to the water, they become discarded bycatch, or discards. Bycatch can be categorized as regulatory, such as fluke under the minimum size limit, or non-regulatory, such as a haul of undesirable skates dumped by a trawler targeting cod and haddock.
One June 1st the Marine Fish Conservation Network released a report on bycatch entitled Turning a Blind Eye: The ‘See No Evil’ Approach to Wasteful Fishing*. The report highlights the enormity of the bycatch problem in U.S. fisheries and reviews regional fisheries council implementation of the bycatch minimization mandates of the Magnuson-Stevens Act, which states that: “Conservation and management measures shall, to the extent practicable, (A) minimize bycatch and (B) to the extent bycatch cannot be avoided, minimize the mortality of such bycatch.”
The report is particularly critical of the federal fishery managers in New England. In 2002, the Northeast groundfish industry harvested 1.79 pounds of bycatch for every pound of fish that was kept and sold. This accounted for 215 million pounds of wasted discards.
At the same time, NMFS has slashed funding for the Northeast Fisheries Observer Program. The Observer Program trains scientific observers to go to sea aboard commercial fishing vessels to track bycatch in commercial fisheries. Lack of funding has resulted in decreases in observer coverage levels, measured in “sea days,” of more than 50 percent overall for New England’s groundfish, herring and scallop fisheries.
The report concludes that fishery managers need to increase the number of observed commercial fishing trips to properly document the unwanted fish and other ocean wildlife tossed overboard, often dead or dying.
“If fisheries managers are going to rebuild New England’s legendary populations of cod, flounder and haddock we need to be able to account for all of the fish and other ocean wildlife that is killed as bycatch in our fisheries. Without this information managers risk further depleting struggling groundfish populations and the health of the ecosystem they depend upon,” said Roger Fleming, a Senior Attorney with the Conservation Law Foundation. “The lack of progress during the last five years in reducing bycatch is unacceptable.”
Bycatch of River Herring
The bycatch of river herring (blueback herring and alewives) is an issue of particular importance to recreational fishermen. When striped bass anglers came out in support of the three-year moratorium on the catching and possession of river herring enacted in November of 2005 in Massachusetts, they sent the message that they were willing to give up access to one of their favorite striper baits to bring back healthy river herring populations. Similar closures in Rhode Island and Connecticut waters have also had the support of the majority of anglers. But while sport fishermen have relinquished their take and many volunteer to improve and maintain herring runs, there is evidence that other factors are playing a role in the catastrophic decline in river herring populations. Some fishermen and scientists are pointing a finger at the Atlantic herring (sea herring) fishing industry, which they say is depleting the population by unintentionally netting river herring.
“In Massachusetts, certainly, we’re concerned about the impact of sea herring fisheries on river systems,” said Dr. David Pierce, Deputy Director of the Massachusetts Division of Marine Fisheries, at a meeting of the Atlantic States Marine Fisheries Commission river herring management board. “It doesn’t take too much river herring being caught in a significant pelagic fishery to have perhaps a rather dramatic effect on the success of a particular river program.” The Atlantic herring fishery is certainly a significant fishery, with annual landings of over 100,000 metric tons captured by purse seiners, midwater trawlers, and a growing fleet of pair trawlers. Pair trawlers, which use two boats measuring around 150 feet in length to pull huge nets capable of holding more than a million pounds of herring, have been singled out as the most likely culprit when it comes to bycatch issues.
The 2005 U.S. Fisheries Atlas of Bycatch*, a report produced for environmental non-profit group Oceana by independent consulting group MRAG, estimated that the Northeastern U.S. Atlantic herring fishery inadvertently captured 539.234 metric tons (1,188,807.47 pounds) of river herring in 2003. For comparison, recreational take of river herring was estimated at 378,540 fish coastwide in 2004 (based on data collected by the embattled Marine Recreational Fishery Statistics Survey). At an average weight per fish of 6-8 ounces, that would be about 200,000 pounds of river herring harvested by recreational fishermen.
The problem is that data on the bycatch of river herring is severely limited, and opinions differ on how this limited data can be extrapolated to estimate total bycatch in the fishery. Authors of the report admit that their estimate is based on a dataset containing significant gaps, and that bycatch monitoring in the Atlantic herring fishery is classified by NMFS as “developing.”
The lack of data is due in part to the nature of the Atlantic herring fishery. It has expanded greatly in the past 10 years as Atlantic herring stocks have rebounded from a collapse in the 1970s and demand for herring as lobster bait has risen. It is considered a relatively “clean” fishery, based on the low amount of bycatch in comparison to the high volume of kept fish. Because of this, coverage by federally trained fisheries observers has historically been low, and most onboard observers were instructed to watch for marine mammal interactions and not to quantify fish bycatch.
In 2004, concern over haddock bycatch in the fishery led to an increase in observer coverage to 312 sea days, and improved protocols for sampling fish bycatch were introduced in October of that year. Detecting river herring bycatch is a challenge; the catch is massive, and in the pair trawl fishery it is pumped directly from the net, sometimes on board one of the two trawlers or onto a designated “herring carrier” boat. Further adding to the challenge is the fact that while dogfish or haddock will stick out like sore thumbs in a pile of Atlantic herring, river herring can be difficult to tell apart from Atlantic herring, and the two species of river herring – alewife and bluebacks – are nearly identical.
A letter to the New England Fisheries Management Council dated June 12, 2006 and written by Jake Kritzer, a marine scientist with Environmental Defense, on behalf of the Atlantic States Marine Fishery Commission and several conservation groups, voiced concern over the quality of river herring bycatch monitoring by federally trained fisheries observers. Discard data from 2004 provided by the Northeast Observer Program lists observed discarding of three times as much “unknown herring” as river herring. The concern is that it is highly likely that some proportion of the unknown herring, as well as some proportion of the nearly 100,000 metric tons of 2004 Atlantic herring landings, is actually unidentified river herring.
The Federal Observer Program has improved sampling protocols and observer training to address the importance of identifying and counting bycatch of river herring. “We stress the importance of correctly ID’ing fish to species; it is the foundation of our data,” said Observer Training Coordinator Tania Lewandowski. “Observers are taught the importance of identifying the different herring to the species level, and that they can co-occur.” Aboard herring trawlers, observers “subsample” the catch by taking a small percentage of the total catch–10 bushel baskets of fish– then separating and weighing the sample by species. This subsample is then extrapolated to determine the amount of bycatch brought on board.
Such improvements to observer training and sampling protocol may very well be in vain as lack of funding is hampering federal observer coverage of the Atlantic herring fishery. In the face of a growing fishery that fished for 2,115 sea days in 2005, federal observer coverage has been cut to only 85 days in 2006, for projected coverage in the range of only 1 to 3 percent.
According to James Becker, scientist with the Maine Department of Marine Resources, such subsampling and extrapolation of a large-volume fishery can over or underestimate the proportion of bycatch in the catch. “Bycatch of river herring in the Atlantic herring fishery is more related to isolated incidents rather than consistent catches of non-targeted species throughout the fishery and over the course of the entire year,” said Becker. “The bigger the sample size, the more accurate the data and the more able we are to extrapolate to the effects of the entire fishery.”
The Maine Department of Natural Resources has initiated a project to look at the retained and landed catch – that which is brought in to portside processors. By sorting through 100% of the bycatch from an entire catch, Becker hopes to get a more accurate estimation of bycatch in the fishery. The portside sampling project achieved about 2% coverage in 2005, and has set a goal for 5% coverage in 2006 and 10% coverage in 2007, dependent on funding.
Massachusetts Division of Marine Fisheries biologist Dr. Michael Armstrong is optimistic that the portside sampling project will provide more information on the extent of the river herring bycatch problem in the Atlantic herring fishery. At this point, there is not enough data to determine how large of an issue the bycatch of river herring really is, and without clear indication of a troubling situation there isn’t enough pressure to increase monitoring. Said Armstrong, “People are talking about river herring bycatch, but nobody’s screaming yet.”