Elsevier

Marine Policy

Volume 30, Issue 4, July 2006, Pages 360-366
Marine Policy

Fleet communication to abate fisheries bycatch

https://doi.org/10.1016/j.marpol.2005.06.003Get rights and content

Abstract

Fleet communication systems report near real-time observations of bycatch hotspots to enable a fishery to operate as a coordinated “One Fleet” to substantially reduce fleet-wide capture of protected bycatch species. This benefits the bycatch species per se, reduces waste, and can provide economic benefits to industry by reducing risk of exceeding bycatch thresholds and causing future declines in target species catch levels. We describe case studies of fleet communication programs of the US North Atlantic longline swordfish fishery, US North Pacific and Alaska trawl fisheries, and US Alaska demersal longline fisheries, and identify alternative fleet communication program designs to reduce fisheries bycatch. Evidence supports the inference that these three fleet communication programs substantially reduced fisheries bycatch and provided economic benefits that greatly outweighed operational costs. Fleet communication may be appropriate in fisheries where there are strong economic incentives to reduce bycatch, interactions with bycatch species are rare events, adequate onboard observer coverage exists, and for large fleets, vessels are represented by a fishery association.

Introduction

Bycatch in marine fisheries is an increasingly prominent international environmental, social, and economic issue [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15], [16]. The issue is addressed as a component in a growing number of broad international resolutions, including Agenda 21 (1992); the Cancun Declaration (1992); UN General Assembly Resolutions 49/118 (1994) and 50/25 (1995); the Rome Consensus on World Fisheries (1995); the UN Food and Agriculture Organization International Code of Conduct for Responsible Fisheries (1995); and the Kyoto Declaration and Plan of Action (1995) [6], [15], [17].

Bycatch, incidental catch that is discarded dead or released injured to a degree that delayed mortality will soon occur [6], can harm ecosystems and economic viability. Some bycatch species of seabirds, sea turtles, marine mammals, sharks, other finfish species are particularly sensitive to increased mortality above natural levels because of their life history traits, including their being long-lived, having delayed maturity, and having low reproductive rates [6], [18]. Other possible ecosystem effects of bycatch include altering biodiversity by removing top predators and prey species at unsustainable levels, and altered foraging strategies by species that learn to take advantage of discards [6]. Economic effects on industry from bycatch include the imposition of a range of restrictions, closed areas, embargos, and possible closures; interference between fisheries, where bycatch in one fishery reduces target catch in another; and if bycatch in a fishery results in mortality of juvenile and undersized individuals of a commercial species before the finfish or shellfish reach their optimal size, this can adversely affect future target species catch levels [6]. And bycatch is a social issue where discarding millions of tons of fish is a wasted food source as well as a waste of animal lives. While global commercial marine fisheries bycatch estimates are based on large assumptions due to incomplete data for many fisheries, including unobserved bycatch such as in abandoned and lost gear, Alverson et al. [1] estimated that in 1994 about 27 million metric tons (27% of the world catch), ranging between 17.9 and 39.5 million tons, of fish per year was discarded at sea. FAO [12] estimated that 1998 global marine fisheries fish discards totaled 20 million metric tons.

Prominent bycatch issues include dolphins and porpoises in purse seines and driftnets; fish discards in shrimp trawls; seabird, sea turtle, marine mammals, and shark bycatch in longlines, purse seines, gillnets, and trawls [6], [19]. For instance, hundreds of thousands of seabirds, including tens of thousands of albatrosses, are caught annually in longline fisheries worldwide, posing a critical global threat to some albatross and large petrel populations [15], [16], [20]. Cumulative turtle mortality in pelagic longline gear worldwide poses a priority threat to sea turtles, in particular, to leatherback (Dermochelys coriacea) and loggerhead (Caretta caretta) sea turtles [13], [14], [21].

There are many strategies to manage commercial marine fisheries bycatch. These include formal constraints through laws, regulations, and policies; multilateral accords; marine protected areas, including area and seasonal closures; best practices for handling and release of bycatch species; changes in fishing gear and methods; eco-labeling; industry self-policing; industry awareness-raising and capacity-building; and fleet communication programs [6], [16]. Multiple methods can be implemented in combination to pursue sustainably managing fisheries bycatch.

Fleet-wide communication programs can report real-time observations of bycatch hotspots, where fisheries bycatch rates of finfish, shellfish, seabirds, sea turtles, and marine mammals are high, so that vessels in the fleet can avoid fishing in the area [22], [23]. Fleet communication is a voluntary form of temporary area and time closures to reduce marine fisheries bycatch. Fleet communication programs have the potential to allow commercial fisheries to operate as a coordinated “One Fleet” to significantly reduce the fleet's bycatch levels and rates. In the short term this could allow an industry to reduce the risk of exceeding government-established seasonal bycatch thresholds. And in the long term this could help prevent a decline in the capture of target species in fisheries where bycatch of juvenile and undersized individuals of commercial species is problematic.

We describe case studies of fleet communication programs of the US North Atlantic longline swordfish fishery, US North Pacific and Alaska trawl fisheries, and US Alaska demeral longline fisheries, and identify alternative fleet communication program designs to reduce fisheries bycatch. We also put the concept of fleet communication programs into context by describing the broad range of strategies for reducing marine fisheries bycatch.

Section snippets

US North Atlantic Longline Swordfish Fishery “Captain's Daily Communication”

Information sources for this case study are John Watson, US National Marine Fisheries Service Southeast Fisheries Science Center, personal communication, 11 August 2004; Nelson Beideman, Blue Water Fishermen's Association, Inc., personal communication, 11 August 2004; Shah et al. [24]; and Watson et al. [25].

In 2001 the Blue Water Fishermen's Association voluntarily established a fleet communication program for the US North Atlantic longline swordfish (Xiphias gladius) fishery, primarily to

Alternative designs for “One Fleet” communication programs

Four central parameters need to be considered when designing a new fleet communication program:

  • Technology for communication: The fleet communication program can use e-mail through satellite-based vessel monitoring systems, e-mail through other satellite-based systems, radio, phone, fax, or a combination of these technologies to facilitate communication between vessels and to transmit data to a designated hub.

  • Observer program: It may be possible to make use of onboard observer data to facilitate

Discussion and conclusions

During a period of seven years when some vessels were not participating in the Alaska demersal longline fleet communication program, the average halibut bycatch rates of non-participating vessels were 10–30% higher than participating vessels, supporting the inference that the fleet communication program reduced halibut bycatch rates. Turtle bycatch rates in the US North Atlantic longline swordfish fishery on traditional J hooks during a research experiment between 2001 and 2003, when industry

Acknowledgments

The authors are grateful for case study information provided by John Watson, US National Marine Fisheries Service; Nelson Beideman, Blue Water Fishermen's Association; Karl Haflinger, Sea State, Inc.; and Janet Smoker, Fisheries Information Services. This study was made possible through funding from the Western Pacific Regional Fishery Management Council. The impetus for this project was to design a pilot fleet communication program for the Hawaii pelagic longline swordfish and tuna fisheries

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