D'Entrecasteaux Channel to stay closed to scallop fishing for forseeable future

​The D’Entrecasteaux Channel has been closed to scallop fishing since 2011 and needs to stay closed for longer, according to the latest survey of the Channel by the Institute for Marine and Antarctic Studies (IMAS).

The survey looked at scallop densities at 76 locations in the Channel, including ten new sites nominated by recreational fishers.

Although it found some small patches of scallops, overall scallop densities were low, with:

  • less than 0.3 scallops per m2 in the northern Channel,
  • between 0.02–0.35 scallops per m2 in the middle area, and
  • between 0.01–0.61 scallops per m2 in the southern Channel.

These numbers are in sharp contrast to the densities of roughly 2.5 scallops per m2 that were observed when the Channel opened to recreational fishing in 2005.

To consider re-opening the D'Entrecasteaux Channel for recreational scallop fishing, scallop densities would need to be above at least one per m2 over most of the Channel. IMAS presented the results of the survey to the Recreational Fishing Advisory Committee (RecFAC) on 28 May. They supported the findings and IMAS and NRE advice that the Channel remain closed.

But if there’s no fishing, why haven’t scallops recovered?

Video of a higher density commercial scallop site observed in the Channel survey. Despite being a higher density site, there were still only 0.43 scallops per m2, less than half the density that would be needed over most of the channel in order to re-open to recreational fishing.

Not enough recruitment

For any fish population to grow, the number of new fish entering the population (recruitment) needs to be more than the number of fish being removed from the population, either through fishing or natural death.

Population  =   Recruitment – Fishing – Natural Death

In the latest survey, IMAS observed very few scallops under the legal size limit, which indicates there hasn’t been a successful recruitment event in the past few years.

So, while the closure means scallops are no longer being removed by fishing, there’s been so little recruitment that the number of new scallops isn’t outpacing natural deaths. The end result is that scallop populations and densities aren’t increasing.

Scallops tend to be a ‘boom and bust’ fishery, meaning a population is generally sustained by one or two very good spawning years in between many more years of poor recruitment. A 'boom' in the form of a large successful recruitment event is what supported fishing in the Channel between 2005 and 2011.

While we don’t know exactly what is needed for a successful spawning year, we do know it’s more likely to happen when scallops are at higher density. 

To help maintain the density of the remaining scallop beds and increase the likelihood of successful recruitment to replenish the population, the Channel will remain closed to fishing for the foreseeable future.


Zero density scallop site in northern channel from 2024 D'Entrecasteaux Channel survey.

Some sites, particularly in the northern Channel had no scallops at all.

Why the D’Entrecasteaux Channel needs to be managed separately

Outside the Channel, scallop populations are interconnected. A bad spawning year in one population can be offset by a better spawning year elsewhere. It also means that if scallops disappear from an area, it could be reseeded by larval scallops carried in on currents from other areas.

Scallops in the D’Entrecasteaux Channel don’t have this luxury. Research has shown that the Channel scallops are virtually a separate population, which means they are entirely self-reliant for recruitment. 

If the breeding population gets too low or disappears, there is very little chance of populations returning to a level that could support fishing, which is why it’s so important to protect the remaining scallop beds.

When will the Channel re-open?

Until scallop densities are high enough (above at least one scallop per m2), there are several year classes of undersize scallops and sufficient above size scallops to harvest, the Channel cannot re-open without risking long term damage to the scallop population. Surveys will continue to be conducted every few years to monitor how the scallop population is doing.

You can find the full IMAS survey results here.

Published on: 6/4/2024


Fishwatch Report illegal fishing

0427 655 557

What to report? arrow button

Contact us

Recreational Fishing

Level 3, 134 Macquarie St

Hobart TAS 7000

Phone: (03) 6165 3233, 1300 720 647

Email: fishing.enquiries@nre.tas.gov.au

Commercial Fisheries

Level 3, 134 Macquarie St

GPO Box 44

Phone: (03) 6165 3000, 1300 368 550

Email: commercial.fisheries@nre.tas.gov.au

Commercial Fisheries Licensing

Level 1, 134 Macquarie St

GPO Box 44

Phone: (03) 6165 3000, 1300 368 550

Email: fishing.licensing@nre.tas.gov.au