• Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust
  • Community of Arran Seabed Trust

Scallops in a changing world

Large scallopsscaledThe International Pectinid workshop (IPW) is the world’s largest scallop conference, attracting fishery scientists and managers from across the globe. We sent COAST ambassador Dr Leigh Howarth to this year’s IPW in Ireland, to present his research on the Lamlash Bay No-Take Zone, and to learn how other countries are managing their scallop fisheries in a changing world.

 

 

Leigh's Report from the The International Pectinid workshop (IPW)

 

Delegates from the EU, USA and further afield were all equally impressed with what COAST had achieved by creating the Lamlash Bay No Take Zone in 2008 and with the now growing evidence that the No-Take Zone is promoting the recovery of seabed habitats and scallop stocks. In their countries, marine protected areas are measures proposed by the Government, not by the local community.

 

Establishing No-Take Zones are one way we can help manage scallop fisheries and improve seabed complexity but it was interesting to learn of other approaches. Along the east coast of the USA for instance, fishery managers have used rotational closures. These involve closing large areas to scallop fishing for 3-4 years, allowing large numbers of scallops to reach minimum legal landing size. The areas are then re-opened to the fishing fleet who are rewarded with large and sustainable catches, before the area is then re-closed. These rotational closures were first put in place in response to plummeting catches and have had a positive impact on scallop fisheries.

 

In China the story couldn’t be more different. Developers there are pumping millions of dollars into scallop aquaculture, meaning Chinese fisheries are increasingly relying on farmed scallops rather than those caught in the wild. Scallop aquaculture begins with rearing tiny scallop larvae in labs, where conditions can be controlled and optimised to maximise their survival. The larvae are then are placed in nets and relocated to the sea, where they grow until they reach maturity. These complex methods seem to be working as the amount of farmed scallops produced by China each year exceeds 200,000 tonnes. That’s 150,000 tonnes more than the amount of wild caught scallops we catch across the entire UK! The Chinese are farming a species known as the Yesso scallop. This goliath of the scallop world can reach the size of a football and its meat alone can weigh over 1kg!

 

Scallop aquaculture is a business that seems to be growing all over the world. However, the industry is facing some serious challenges. The nets they use to grow the scallops in often become encrusted with a thick mat of seaweeds, barnacles, sea squirts and other marine life. Not only is removing this carpet of life difficult and expensive, it also reduces the flow of water entering the scallop nets, reducing food supply and killing the scallops within.

 

To address this, Dr Sandy Shumway and colleagues have produced a new chemical to coat the nets used by scallop farmers. When exposed to light, this special coating reacts and releases small quantities of hydrogen peroxide which keep the nets clean of life. These chemicals are intended to be cheap to produce, safe to scallops and non toxic to the surrounding environment.

 

Scallop stocks all over the world are becoming increasingly under threat from overfishing, pollution, disease, ocean acidification and climate change. However, the many passionate scientists and fishery managers I met at the International Pectinid workshop show that some of these challenges can be met providing governments, scientists and fishermen keep working together for a better, more sustainable scallop industry.

 

Following his talk, Leigh was presented with the award for Best New Investigator Talk. He would like to thank COAST for providing him with the opportunity to attend the International Pectinid workshop (IPW 2015).

 

Scallop aquaculture in China