Help fish thrive
University
of Washington
The study, led by Michael Melnychuk of the University of Washington's School of Aquatic and Fishery Sciences, draws upon the expertise of more than two dozen researchers from 17 regions around the world.
The research team analyzed the
management practices of nearly 300 fish populations to tease out patterns that
lead to healthier fisheries across different locations. Their findings
confirmed, through extensive data analysis, what many researchers have argued
for several years.
"In general, we found that more management attention devoted to fisheries is leading to better outcomes for fish and shellfish populations," Melnychuk said. "While this won't be surprising to some, the novelty of this work was in assembling the data required and then using statistical tools to reveal this pattern across hundreds of marine populations."
The
research team used an international database that is the go-to scientific
resource on the status of more than 600 individual fish populations They chose
to analyze 288 populations that generally are of value economically and
represent a diversity of species and regions. They then looked over time at
each fish population's management practices and were able to draw these
conclusions:
In
regions of the world where fish and shellfish populations are well studied,
overall fisheries management intensity has steadily increased over the past
half century
As
fisheries management measures are implemented, fishing pressure is usually
reduced toward sustainable levels, and population abundance usually increases
toward healthy targets
If
fish populations become depleted as a result of overfishing, a rebuilding plan
may be implemented. These plans tend to immediately decrease fishing pressure
and allow populations to recover
If
strong fisheries management systems are put in place early enough, then
overfishing can be avoided and large, sustainable catches can be harvested
annually, rendering emergency measures like rebuilding plans unnecessary
The
study builds on previous work that found, by using the same database, that
nearly half of the fish caught worldwide are from populations that are
scientifically monitored and, on average, are increasing in abundance. The new
paper takes a closer look at specific management actions and how they have
impacted fishing pressure and the abundance of each population examined, Melnychuk
explained.
"All
fish populations have their own unique contexts that might dictate what
management tools would be most helpful and promising to use," he said.
"Despite the great diversity in their management objectives and various
strategies to meet those, we focused on key management tools in common to many
fisheries around the world."
The
international research team chose to look at a spectrum of fish populations,
such as hakes in South Africa and Europe, orange roughy in New Zealand, tuna
species on the high seas, anchovies in South America and scallops off the
Atlantic coast of North America. Most of the populations they examined had a
history of being depleted at some point, usually due to historical overfishing.
For
example, with U.S. mid-Atlantic population of black sea bass, a rebuilding plan
instituted in 1996 brought fishing rates down from three times the sustainable
level to below this mark, which led to a steady rebuilding of the fishery and
full recovery by 2009.
"Fishers
targeting black sea bass in the northeastern U.S. are finally reaping the
rewards of harvest caps that allowed the population to rebuild," said
co-author Olaf Jensen of the University of Wisconsin -- Madison. "The 2020
catch limit of more than 6,000 tons is the highest since catch limits were
first imposed more than 20 years ago."
This analysis omits fisheries that lack scientific estimates of population status, even though these account for a large amount of the world's catch.
These include most of the fish populations in South Asia and Southeast Asia -- fisheries in India, Indonesia and China alone represent 30% to 40% of the world's catch, most of which is essentially unassessed.
Although fisheries in
these regions could not be included in the analyses, the paper's authors conclude
that lessons learned can equally apply to data-limited fisheries: Greater
investment in fisheries management systems is expected to lead to better
outcomes for the fish populations upon which our fisheries are based.
A
full list of paper co-authors is available in the paper. This research was
funded by The Nature Conservancy, The Wildlife Conservation Society, the Walton
Family Foundation and a consortium of Seattle fishing companies.
