This week it has been brought to my attention that there is a proposal to dredge for scallops inside a ‘Special Area of Conservation’ located in Cardigan Bay, Wales.  This proposal has divided opinions.  On Twitter this week Professor Callum Roberts, a marine conservation biologist at the University of York (UK) lamented that there was ”No hope for UK marine conservation if this mad proposal to scallop dredge in a protected area goes ahead” .  Dr Magnus Johnson, a Crustacean Fisheries and Ecologist researcher at the University of Hull (UK) quickly countered “It is worth reading the science by first!”, following with a couple of hashtags “#eatmorefish #eatmoreshellfish”.  Two scientists, with two opposing views… what is going on?

What is a Special Area of Conservation anyway?

These are something unique to the European Union.  They arise from the Habitats Directive, first adopted in 1992 in response to a European convention called the Berne Convention.  Special Areas of Conservation (SAC) are designed to protect a number of habitats and species (plants and animals) considered endangered, vulnerable, rare, or endemic.  Once a SAC has been formally designated, the establishment and implementation of management measures are largely left down to the individual Member State.  However, there are certain things that they must do.  Briefly, under Article 6 of the Habitats Directive, these include:

• Take appropriate steps to avoid the deterioration of natural habitats and the habitats of species as well as significant disturbance of the species for which those areas have been designated.

• Ensure that a legal consent procedure is in place for any plans or projects not directly connected with or necessary to the management of the site but likely to have a significant effect thereon, either individually or in combination with other plans or projects, to ensure that the integrity of the SAC is not adversely affected

What is so special about this particular SAC?

The Cardigan Bay (known as Bae Ceredigion in Welsh) SAC is 95,860.36 hectares (approximately 959 square kilometres) in size.  It’s designation primarily came about to protect one of the two semi-resident population of bottlenose dolphin (Tursiops truncates) in UK (England, Wales, Scotland, Northern Ireland) waters.  Apparently they are also the UK’s largest breeding population (but I cannot confirm that).  The bottlenose dolphin is one of the species listed for protection in Europe under Annex II of the Habitats Directive.  It’s not all about dolphins though.  When designating a SAC you can also add ‘qualifying features’ that are not a ‘primary reason for selection’ of a site.  In this particular area, qualifying features are permanently submerged sandbanks, rocky/cobble reefs, sea-caves, sea lamprey, river lamprey, and grey seals.  Of course these aren’t the only species and habitats that are now covered under the SAC.  Scallops are also found there.  In fact, out of the whole bay, only 20% of it is covered with scallop beds – a chunk of which now sits inside the SAC.

Current fishing status in the SAC

Currently, scallop dredging is allowed in part of the SAC.  The current proposal wants to open more.  These areas proposed for closure were done so after a significant increase in scalloping in the area.  This raised concerns that the fishery would be damaging to some of the very features that deemed SAC designation necessary – namely physical impact on cobble reefs, and impact on seafloor (benthic) organisms – the food sources for fish that dolphins eat.

It is worth noting that beam trawls area already allowed to operate in the whole SAC.  Dredgers and beam trawls are both towed fishing gear aimed at bottom-dwelling species.  Beam trawls are towed on the top of the seabed often with 'ticklers' - chains that run on the seafloor surface to 'encourage' fish into the net,  whilst dredgers have ‘teeth’ that dig into the seafloor to capture critters lurking under the surface.  There are environmental concerns with both methods, but that is for another post.

Why open the closed areas?

According to the Welsh government, the reason the SAC closures “need” to be opened is because the other areas have been significantly depleted.  In the current closed areas, scallops are abundant.  The government then goes on to say that there is a “concern that these scallops may not be reaching their potential growth rate due to overcrowding and competition for resources” .  Why is it a problem that these animals are essentially living and dying all by themselves?  The government have the answer – “The current situation, therefore, does not optimise the sustainable use of this natural resource”.  Remember fishing isn’t just about food - it is also about economy and people.  Giving economic opportunities for people is important.  In the consultation, the Welsh Government estimate the new proposals could result in another £6 - £10 million per year entering the Welsh economy.  Not something to be sniggered at.  But if I may interject with an opinion here, this reasoning is a perfect example of how we commodify the ocean and its inhabitants.  The idea that everything on this Earth is for our use is a subject of debate.

The reports

Dr Magnus Johnson, in his Tweet linked to a press release from Bangor University on some research done by their Fisheries and Conservation Science Group.  “World’s largest ever fishing impact study brings hope for Cardigan Bay Scallop fishermen” the title reads.  The story is that the study “focused on understanding the amount of scallop fishing within the SAC that would be considered sustainable and that would not damage the conservation features of the area”  The press release links to three reports* (Reports 59 - 61) looking at the impact of dredging in the SACs infauna (things in the seafloor), epifauna (things living on the seafloor), and impact to the physical environment.  Lots of details in these three reports which would make this post even longer if I was to cover, but I have added a link to them at the bottom of this post for those who want to take a closer look.  Essentially the reports suggest that with careful management (e.g. rotational-open/closed areas to allow recovery, gear restrictions, control on how much fishing can occur (effort control), scallop dredging can occur with minimal impacts to the features of concern within the SAC.

Some additional points

• Parts of the SAC were only finally closed to dredging in 2010. Is five years long enough to see full recovery? Is full recovery even possible? We don’t know for sure, because we don’t know what the state of this part of the ocean was prior to dredging, but it seems unlikely given the lifespan of organisms, repopulation rates, and alteration of the ecosystem. In addition the SAC is open to beam trawling, meaning the physical nature of the SAC and epifauna diversity in particular is continuously being altered. This is an issue when using such areas as comparisons for calculating damage and recover rates like this research has, because we are comparing recovery of already impacted areas, not to untouched ‘pristine’ areas (good luck finding some!).

• Muddy bottom doesn’t appear to be given much value. Actually this is a wider issue – we undervalue the role of this sort of habitat because it does tend to have lower diversity than other areas in the ocean. How we ascribe value to habitats is also a subject for another post

• The work, it seems, was always about deciding how much dredging should be allowed. Would a better question have been to ask if dredging should be allowed in the first place, and if so how much? Let take a look at the aim of the Welsh Government in opening the SAC to further dredging - “establish a viable and sustainable scallop fishing within the Cardigan Bay SAC”…

• The work does not in any way imply that degradation to the area and its inhabitant populations will not occur. Of course it will. In situations like this, what we are dealing with are trade-offs. We want to eat our scallops, we want lots, and we don’t want to pay the price for hand-diving. Given these demands, how much damage are we willing to inflict? Does the cost (to humans or other animals) outweigh the value we receive?

• Thinking outside the SAC, it seems that the scallop fishery has been extremely poorly managed. If it was not, and the fishery was indeed sustainable, depletion in scallops outside the closed area should not have occurred. This approach to fishery management should be utilized elsewhere and not just inside these proposed areas. We can’t have sustainable fisheries by only managing our activities in a few pockets – this needs to have wide-scale implementation.

What about the dolphins?

The SAC was primarily designated for the dolphins, so can dredging impede them in any way?  According to an article by journalist George Monbiot in The Guardian Newspaper, a study by the Welsh Government (not available online) notes that bottlenose mothers with calves rely on small/sedentary animals living on the seafloor for feeding as they cannot travel far with their young.  We also know other dolphin populations hunt prey lurking beneath the sea floor.

The main concern in terms of dolphin food was that the loss of fish the dolphins hunt due to the loss of benthic species from scallop dredging.  Given dredging occurs elsewhere in the bay, have the dolphins suffered at all?  Have the fish on which they depend suffered?   Do the dolphins particularly rely on this same area that fisheries want to use?  I’ve had a look and I can’t find anything specific to the area, so I’d say… we don’t know.

*These particular pieces of science has been presented in reports but not in a peer-reviewed journal.  This does not make the science flawed or inaccurate, but it has not gone through the same process for publication as would be needed for publication in a scientific journal.

Minor Edits - 26 November 2015:

• I have clarified where the figure '£6-10 million per year entering the Welsh economy' came from (the consultation document).

• I have added that ticklers are often used on beam trawls