CHOIR: Coalition for the Atlantic Herring Fishery's Orderly, Informed, and Responsible Long-Term Development


« Back to All Media

Myth: Midwater trawl observer data is reliable

November 10, 2007


Over the last year, members of the midwater trawl fishery have tried to argue that observer levels on their vessels are sufficient to tell us anything about the bycatch or discards on these vessels.

For example, the newly-formed “Sustainable Fisheries Coalition”, a group of midwater trawl vessels and their processors, put out a press release just recently in which trawler lobbyist Jeff Kaelin said that “There’s actually some good data on bycatch…and our bycatch levels are extremely low.”

Good data? By whose standards?


Between 1994 and 2005, the NMFS Sea Sampling (Observer) program, “the primary source of bycatch data” for the Council, saw dismal rates of observer coverage in the herring midwater trawl fleet.*

Between 1994 and 2005, over 5,663 single midwater trawl (MWT) trips were taken. During that same period, 4,086 pair midwater trawl (PMWT) trips were taken. Only 85 of those 5,663 MWT trips carried observers, a rate of 1.5%. And only 173 of the 4,086 PMWT trips carried observers, a rate of 4.2%.

Combined, there were 9,749 total midwater trawl trips taken between 1994 and 2005, and only 260 of these trips carried observers. In other words, in that time period, there was a 2.66% coverage rate in the midwater trawl fishery. Yes, that is correct, 2.66%.

Now, would you call that a sufficient level of coverage? Do you think that any bycatch data based on that level of coverage would be reliable?

Keep in mind that in some parts of the country, vessels like this would be carrying 100% observer coverage. (In Alaska, any trawler over 124 feet in length is required to carry 100% coverage. And vessels between 60 and 124 feet must carry at least 30% coverage. Many of the midwater herring trawlers off New England are well over 124 feet, with many in the 140-165 foot range.)


The other source of observer data often mentioned by the midwater lobby is the data from a study done by the Maine DMR between 1997-1998. A grand total of 27 midwater trawl (single and pair combined) trips were observed during that study. Or, Amendment 1 points out, “The report notes that midwater trawlers made about 800 trips annually around 1997-1998, so the sample of 27 midwater trawl trips represents about 3.5% of all midwater trawl trips.”

Again, the results of this study were based on a meager 3.5% coverage rate.

Why do observer coverage rates matter?

The reason observer levels matter is because if you have an insufficient level of coverage, vessels can alter their fishing patters to avoid problems. Unless you observe an adequate level of trips, the data is essentially meaningless.

For example, with such meager levels of coverage, the herring midwater trawl fleet would never tow near bottom if they have an observer onboard. If you have to carry an observer a handful of times a year, you can bet that you will do everything you can to alter how you fish for those handful of trips.

(And while the ‘Sustainable Fisheries Coalition’ claims otherwise, it is well known that herring midwater trawls fish near bottom. This is clear from anecdotal accounts and from management documents like Herring Amendment 1. For example, read Appendix 6 of the Amendment. And Framework 43, which was needed because of serious herring trawl interactions with haddock on Georges Bank, clearly indicates that these vessels catch haddock, a species that lives and spawns on bottom. In order to catch species that live on bottom, you need to be fishing near bottom. In 2004, for example, 2 vessels were caught landing almost 50,000 pounds of juvenile haddock.)

The key is to put enough observers onboard so that vessels cannot alter habits while they have an observer. That goes both for bycatch levels and the amounts of discards.

Would you consider the coverage levels described above to be adequate? Didn’t think so. Keep that in mind the next time you hear the midwater trawl lobby trying to tell you anything about bycatch data in the midwater trawl fleet.

Solution to the problem

We need to see a sufficient level of observer coverage on midwater trawl vessels. Put enough observers on these vessels so that we can have an accurate picture of what is happening in this fishery in regards to bycatch and discards. Until then – as long as we operate with such scant observer coverage- we will continue to manage this fishery with inadequate data.

The midwater trawl fishery insists it is clean. If that is true, they should be jumping on every opportunity to prove us all wrong. What is the concern over an increased level of observer coverage if in fact there are no problems with bycatch and/or discards?

*This data taken from the NEFMC’s ‘Final Herring Amendment 1’, pages 298,339, 353 and 360-364; and from the NEFMC 2007-2009 Proposed Specifications for the herring fishery, page 51.

Hosting • Design • Development: Community Internet Cape Cod Web Design