Indian Ocean concerns
The setting of overall commercial catch limits for billfish, tuna,
sharks and other highly migratory species in the Indian Ocean
was undertaken in June, but as outlined by Jason Schratwieser,
the IGFA’s Conservation Director, there is reason for concern.H
ighly migratory species (HMS) such as tunas, billfishes and sharks move around quite
a bit and don’t respect national borders. As such, management of these critters is
largely the responsibility of international Regional Fisheries Management Organizations
(RFMOs). Globally, there are four big players responsible for managing these pelagic
gamefish. These include the International Commission for the Conservation of Atlantic Tunas and
the Indian Ocean Tuna Commission (IOTC). As the Pacific Ocean is such a large body of water,
HMS management is shared by the Western and Central Pacific Fisheries Commission and the
Inter-American Tropical Tuna Commission.
Unfortunately, as far as billfish are concerned, most of these RFMOs are not doing a good
job of managing stocks at sustainable levels, something that should concern billfish anglers
around the world.
This June, the IOTC convened its annual meeting in Hyderabad, India. In line with its observer
status, the IGFA submits position statements in advance of the annual meetings of the IOTC,
as well as the other three major RFMOs. Below is an outline of the current situation for billfish
stocks in the Indian Ocean and what the IGFA had to say about it.
BLACK MARLIN
The 2015 assessment on black marlin indicated that there was at least an 80% probability of
this stock being overfished or experiencing overfishing. However, the new 2018 assessment
indicates that the stock is not currently overfished or experiencing overfishing. That said,
the IOTC Scientific Committee voiced concern about the high degree of uncertainty of the
2018 assessment and concluded that the results should be interpreted with caution, citing
sharp increases in total catches from 15,000 tonnes in 2014 to over 20,000 tonnes since- Current catches of more than 20,000 tonnes are higher than the maximum sustainable
yield (MSY) target of 12,930 tonnes, which would indicate that the change in stock status
is an unlikely scenario without any rebuilding trend. In addition, the uncertainty of the new
assessment has precluded managers from producing stock predictions for this species.
The IGFA recommended that the Commission revisit the results of this stock assessment in
order to generate stock projections and immediately reduce the total catch to a level below that
of MSY to account for uncertainties in the assessment.
BLUE MARLIN
Although the stock is still experiencing overfishing, no assessment was conducted in 2018. The
IOTC Scientific Committee also noted uncertainties with catch data and that current catches
are exceeding the limit imposed in 2018.
Therefore, the IGFA recommended that the Commission lower total catch of blue marlin to no
more than 10,780 tonnes, as current catches are exceeding management recommendations.
STRIPED MARLIN
The Indian Ocean striped marlin stock is of particular concern. Preliminary research suggests
that striped marlin comprise a single stock in the Indian Ocean that is distinct from Pacific
Ocean fish, indicating little to no contribution of biomass from other areas. The 2018
assessment indicates that striped marlin stocks are in a severely depleted state due to two
decades of overfishing and is experiencing fishing mortality nearly double what would produce
maximum sustainable yield.
In order to give the stock a 70% chance of rebuilding by 2024, the IGFA recommended that
the maximum overall catch not exceed 1500 tonnes annually. It deems any less of a reduction
in catch unacceptable for a stock that has been overfished for this long a period.
SAILFISH
No new assessment was conducted in 2018 and stock status is still determined by the 2015
assessment that incorporated data-poor methods. While Sailfish are still considered to be
subject to overfishing, they are not considered to be overfished. Catches are still higher than
the recommended 25,000 tonnes. To address this, the IGFA recommended that the Commission
impose a total catch limit of 20,415 tonnes.
By the time you read this, the IOTC meeting will havetaken place. Hopefully, billfish stocks
will see some better conservation measures enacted.
THE IGFA
JASON SCHRATWIESER
serves as the International
Game Fish Association’s
Conservation Director, a
position he has held since
2003. He also runs the IGFA’s
Great Marlin Race (IGMR)
program and was integral in
having the Billfish Conservation
Act (BCA) passed by the US
Government in 2012. Jason is
an avid angler and has been
working on fisheries policy
and management issues for
the last 18 years.
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