Biologo

F I S H and F I S H E R I E S , 2005, 6, 350–361

Wasted fishery resources: discarded by-catch in the USA
Jennie M Harrington1, Ransom A Myers2 & Andrew A Rosenberg3
1

MRAG Americas, Inc., Eastern Ave, Essex, MA 01929, USA; 2Biology Department, Dalhousie University, Halifax, NS,

Canada B3H 4J1; 3Ocean Process and Analysis Laboratory, Institute for the Study of Earth, Oceans and Space,University of
New Hampshire, Durham, NH 03824, USA

Abstract
Fishery by-catch, especially discarded by-catch, is a serious problem in the world’s
oceans. Not only are the stocks of discarded species affected, but entire trophic webs
and habitats may be disrupted at the ecosystem level. This paper reviews discarding
in the marine fisheries of the USA; however, the type, diversity and regulatorymechanisms of the fisheries are similar to developed fisheries and management
programmes throughout the world. We have compiled current estimates of discarded
by-catch for each major marine fishery in the USA using estimates from existing
literature, both published and unpublished. We did not re-estimate discards or discard
rates from raw data, nor did we include data on protected species(turtles, mammals
and birds) and so this study covers discarded by-catch of finfish and fishable
invertebrates. For some fisheries, additional calculations were required to transform
number data into weight data, and typically length and weight composition data
were used. Specific data for each fishery are referenced in Harrington et al. (Wasted
Resources: Bycatch and discards in US Fisheries, Oceana,Washington, DC, 2005).
Overall, our compiled estimates are that 1.06 million tonnes of fish were discarded
and 3.7 million tonnes of fish were landed in USA marine fisheries in 2002. This
amounts to a nationwide discard to landings ratio of 0.28, amongst the highest in the
world. Regionally, the southeast had the largest discard to landings ratio (0.59),
followed closely by the highly migratoryspecies fisheries (0.52) and the northeast
fisheries (0.49). The Alaskan and west coast fisheries had the lowest ratios (0.12 and
0.15 respectively). Shrimp fisheries in the southeast were the major contributors to
the high discard rate in that region, with discard ratios of 4.56 (Gulf of Mexico) and
2.95 (South Atlantic). By-catch and discarding is a major component of the impact of
fisheries onmarine ecosystems. There have been substantial efforts to reduce bycatch in some fisheries, but broadly based programmes covering all fisheries are
needed within the USA and around the world. In response to international
agreements to improve fishery management, by-catch and discard reduction must
become a regular part of fishery management planning.

Correspondence:
Andrew A.
Rosenberg, OceanProcess and Analysis
Laboratory, Institute
for the Study of Earth,
Oceans and Space,
Morse Hall 142,
University of New
Hampshire, Durham,
NH 03824, USA
Tel.: +1 603 862 2020
Fax: +1 978 768 3878
E-mail: andy.
rosenberg@unh.edu

Received 23 Aug 2005
Accepted 13 Oct 2005

Keywords by-catch, discard, overfishing, USA fisheries, waste

Introduction

351

Methodology

352Discarded by-catch estimates for the 27 major fisheries in the USA

354

Discussion

354

350

Ó 2005 Blackwell Publishing Ltd

Fisheries discards in the USA J M Harrington et al.

Acknowledgements

360

References

360

Introduction
The unintentional capture of non-target species of
fish, mammals, turtles, birds and invertebrates is a
well-recognized feature of fisheries aroundthe
world. Usually termed by-catch, some of the captured organisms may be retained for sale or use,
while others are discarded back into the sea because
of either low value or regulatory requirements.
Survival rates for discarded by-catch are highly
variable (Chopin and Arimoto 1995; reviewed
in Alverson et al. 1994; Davis 2002), as are
the impacts of by-catch on marine ecosystems
(Hall...