Fisheries bycatch is the most immediate and urgent threat to many endangered marine species. The Consortium is an unprecedented collaboration of entrepreneurial fishermen, engineers and marine biologists to research and develop conservation engineering solutions.

Project Objectives

  • Support collaborative research between scientists and the fishing industry that leads to the development of practical fishing techniques for avoiding the depletion of species endangered by excessive bycatch
  • Understand interactions between threatened non-target species and fishing operations
  • Research and develop bycatch reduction methods
  • Facilitate global exchange of information on bycatch reduction technologies

Research Overview

The Aquarium is a founding member of the Consortium for Wildlife Bycatch Reduction, launched in 2005 as a science-industry partnership to reduce bycatch in threatened non-target animals. Its other members include Blue Water Fishermen’s Association, Duke University, Maine Lobstermen’s Association and the University of New Hampshire. The goal of the Consortium is to support collaborative research between scientists and the fishing industry that leads to the development of practical fishing techniques for avoiding the depletion of species endangered by excessive bycatch.

What is bycatch?

Getting seafood to the dining table comes at the expense of endangered species, which too often perish in the nets and hooks set to capture the fish and shellfish we eat. The collateral mortality of non-target marine animals in fishing is referred to as “bycatch,” and is one of the principal threats to marine biodiversity worldwide.

Why does bycatch occur?

Much of the fishing industry is very specific about what species it targets for capture. Unfortunately, other animals become hooked or trapped either when attracted to the bait or target catch, or when simply unable to avoid capture or entanglement in fishing gear. One of the most widely publicized examples of bycatch was in the 1970s, when many learned about dolphins killed in tuna purse seine nets in the Pacific. Although solutions to that problem have been developed and implemented, it is only one example of a widespread problem occurring in all fisheries, in all seas, and that spares no group of animals, from delicate corals to massive whales.

How serious is bycatch?

Many would argue that even though the unintentional loss of marine life is tragic, bycatch is an acceptable consequence to supplying the world with wild-caught seafood. However, when the scale of mortality reaches many thousands it threatens the very survival of species and the environments in which they form an integral part. Every year across the globe, at least 7.3 million tons of marine life is caught incidentally by fishing. In some fisheries the percentage of bycatch far outweighs the amount of target catch. For example, for every shrimp caught by nets dragged behind boats (or trawls) in the Gulf of Mexico, over four times its weight is made up of bycatch.

If the problem is ignored, the result too often is depletion or extinction of endangered animals. In 2007 the world learned that the baiji, a freshwater porpoise found only in China’s Yangtze River, finally succumbed to decades of incidental hooking among other causes of mortality, and is now believed to be effectively extinct. In the Northwest Atlantic, Canada and the USA are working to ensure that the North Atlantic right whale, now numbering some 400 individuals, does not suffer the same fate from fatal entanglements in fishing lines. These are not rare examples, but part of a systemic problem occurring worldwide.

Bycatch also takes its toll on fishermen. It results in damaged gear, reduced catches, and fishing restrictions that threaten their economic survival.

What can be done about it?

The good news is that there are solutions to the threat that bycatch poses to endangered species. One approach is to reduce fishing or direct it away from hotspots of conflict between fishing operations and non-target animals. There are also fishing technologies and methods that keep the fishing industry active but that reduce bycatch to levels at which it no longer poses a threat to the survival of non-target species. The challenge is to identify the most practical solutions in collaboration with the fishing industry.

What is the role of the New England Aquarium?

The New England Aquarium has been a leader in bycatch research and mitigation technologies since the early 1990s. Its research staff has conducted studies in the Gulf of Maine to measure rates of survivorship in cod and dogfish captured as bycatch. Prior to this research, no one knew for certain how many species survived following the stress and trauma of capture in fisheries. In a major field experiment carried out with fishermen, acoustic “pingers” placed on gillnets were shown conclusively to reduced the bycatch of harbor porpoise in the Gulf of Maine by an order of magnitude (see Kraus et al., 1997 PDF). Further evaluations of these acoustic deterrent devices were made in New Zealand and Argentina. This work led to mandated use of pingers in a number of gillnet fisheries in the US and the technique has spread to other fisheries around the world. It also highlighted the monumental gains in bycatch reduction that could be achieved by having science and industry working in collaboration.

Examples of Projects Supported


  • Spatial analysis of fishing gear-loggerhead turtle “hotspots” of conflict in North Carolina.
    • Results: Analysis used by fisheries managers to ensure that fishing areas were outside main areas of conflict.
  • Evaluation of earth magnets as a deterrent for shark bycatch.
    • Results: The degree of aversion response varies across species. The deterrent effect in some species is strong enough to warrant further research as a potential bycatch mitigation method.


  • Research and development into reducing bycatch by using gillnets manufactured with a small amount of barium sulfate
  • Understanding the behavior of pilot whales in longline fisheries, North Carolina
  • Research and development of fishing devices for reducing bycatch of sea turtles and large whales in the Northwest Atlantic, including highly durable sinking groundline and innovative vertical line technologies
  • Modeling right whale-fishing rope entanglements in the Northwest Atlantic
  • Building networks and mechanisms for exchanging information internationally on best practices in bycatch reduction through gear workshops, annual meetings, publications and on-line searchable databases of bycatch reduction techniques (