Category Archives: Fisheries, Aquaculture, & Sustainable Seafood

How special is a ‘Special Area of Conservation?

 

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:

Continue reading How special is a ‘Special Area of Conservation?

Oh Canada – what about your ocean?

This is a big post.  It’s about big things.  Important things too.  It deals with Canada – a big country.  Actually by area, it is the second largest country in the world.  It also has a lot of ocean under its jurisdiction.  Take a look at the website of Fisheries and Oceans Canada, a Federal government body, and you will see statements like this:

“The Government of Canada is working to ensure the future health of Canada’s oceans and ocean resources by increasing understanding and protection of our oceans; supporting sustainable economic opportunities; and demonstrating international leadership in oceans management”

Sounds good doesn’t it.  The Canadian Federal Government (which has just changed as of yesterday – see bottom of the post) have a several Acts in place to govern the bit of the ocean they have claimed as theirs.  Great stuff!  Except maybe, as demonstrated in a recently published paper, authored by 19 Canadian scientists including lead-author Megan Bailey (Dalhousie University), “over the past decade decision-making at the federal level appears to have undermined the government’s own mandates for the sustainable management of Canada’s oceansContinue reading Oh Canada – what about your ocean?

How deep is too deep for commercial fishing?

Our ever-improving technology has allowed us to fish longer, catch more, and move further from land.  It has also allowed us to fish deeper.  EU statistics indicate that between 1950 and 2006 fishing depths increased from an average depth of 407 metres, to 535 metres.

Life in the deep is slow-paced.  Food is scarcer than in the sunlit surface waters.  Species grow slower and live longer.  Some deep-sea corals, like the one in the image, are thought to be over 4,000 years old. Traits like these are why organisations like Marine Conservation Institute that ” The deep-sea is the world’s worst place to catch fish” .  It’s not just the sustainability of targeted species that is causing concern, but of those caught as bycatch, as well as damage to the seabed and the flora and fauna living in and on it – like the coral in the photo.  So can deep-sea fishing ever be managed sustainably?    A recently published study from Joanne Clarke, a PhD student at the University of Glasgow, and colleagues suggests that there might be a way to make the practice less damaging. Continue reading How deep is too deep for commercial fishing?

Reducing bycatch of skates and rays – stop tickling them!

Bottom-trawl fisheries may supply us with much of the tasty fish we like to enjoy, but it does come with its problems.  Also known as ‘dragging’, bottom trawling essentially involves dragging a large net, held open either with a beam (beam trawling) or large metal/wooden ‘doors’ (otter trawling) along the sea bed, or just above it.  It is used to catch a range of commercial species like cod, shrimp, flounder, and halibut.  One of the problems of trawling is that it is not a very selective form of fishing.  Other species are caught in the process, and this bycatch can include at risk species such as skates, rays and sharks.  As well as ecological implications, bycatch can be bad for fishers, who often end up throwing away bycatch either because it isn’t worth anything, or because they are not allowed to land it.  Bycatch reduction is a win-win for fishers and for the marine life caught.

Reducing bycatch of sharks, rays, and skates (collectively known as elasmobranchs) in bottom trawls is one of the many fishery-related issues on the mind of scientists at Marine Scotland Science.  As this piece of research from the Marine Scotland Science team shows, one possible solution (though not perfect) may not be all that tricky to implement. Continue reading Reducing bycatch of skates and rays – stop tickling them!

Climate Change Impacts on Kenya’s Fishery-dependent communities

 We now have a number of scientific studies that tell us how climate change is altering coral reef ecosystems, but how will these changes impact on communities that depend on them for their livelihood?  According to Joshua Cinner of James Cook University in Australia and colleagues from around the world, that answer depends more on the  community capacity for adaptation than its location.

Fishery-dependent communities in Kenya are not in a great situation.  Their reefs were heavily affected by a massive bleaching event in 1998 that has been linked to an extreme El Niño event and have not necessarily recovered as well as we might hope, and Kenyan reefs are likely to face increasing amounts of climate-related stress into the future.  Across three years, Cinner and co surveyed 15 ecological sites associated with 10 coastal communities along the Kenyan coast.  Using a range of ecological indicators of vulnerability of these reefs, they linked up the ‘health’ of the ecosystems with the vulnerability of the human communities that depend on them. Continue reading Climate Change Impacts on Kenya’s Fishery-dependent communities

Community-based conservation to rebuild fish stocks

I don’t know about you, but I wouldn’t mind being there right now. This is one of the Fijian islands in the Pacific, and the second largest in the group.  As serene as the picture is, not all is serene for the Islanders.  Fishers in Nagigi, a small community based on the south coast of Vanua Levu Island have been noticing that the number of fish and the size of fish have been decreasing, and habitat degrading – a big problem for a community heavily dependent on its marine resources.  This decline isn’t necessarily down to big foreign boats coming in and taking the critters on which they depend.  Instead, overexploitation and habitat destruction seems to arise from the ever-increasing number of locally based fishers.  The source of this claim?  The villagers of Nagigi.

In this paper,  Abigail Golden from Columbia University and fellow researchers explore the idea of setting up a short-term no take marine protected area within Nagigi’s coastal tenure area (known aqoliqoli ).  This idea hasn’t come from the researchers nor from any top-down government as tends to happen in western countries.  Instead the idea has come from the village leaders themselves.  This sort of bottom-up governance is far from unheard of.  The Pacific Islands are small and numerous, and have a long history of small areas of land and coastal waters managed by local communities.  Some have worked well, some have not, and many have come under strain or been lost through both technological developments, increasing population, increasing demands for resources, and cultural change.  Still, a well-managed community based MPA can work well, particularly in these remoter locations, and especially were more rigorous research and recording is absent.  Regardless of where you are in the world, there are a number of vital steps needed for good management.  One involves getting as much information as possible – about the species that are there now, the fishing methods used, an idea of how conditions have changed, and perceptions towards different management methods.  The other involves bringing the local community into the conservation planning in a meaningful way.  So the team went out and conducted two types of surveys – one looking at the species living on the reef at the time, and one talking to some of the villagers themselves. Continue reading Community-based conservation to rebuild fish stocks

Australia’s protected area network fails to adequately protect the world’s most threatened marine fishes

Australia has, compared to some other countries, a fairly extensive network of both marine and terrestrial protected areas.  On the marine side there is of course the Great Barrier Reef Marine Park and more recently the implementation of the Commonwealth Marine Reserve network.  The idea behind any marine protected area is to offer long-term “conservation of nature with associated ecosystem services and cultural values”, so one would expect to see some effective protection going on in these areas…right?  Areas chosen, and cared for to ensure they offer conservation value, to do all we can to help keep species going that have suffered population declines because of our actions?  I’m sure many of you won’t be surprised to hear that this isn’t always the case.  Take a look at some of my previous posts – here here, and here.  Unfortunately, as highlighted in a recent study by Karen Devitt, who was based at Charles Darwin University at the time of writing, Australia’s protected areas are inadequate for protecting one of the world’s most threatened marine fishes – the sawfish.

There are 5 species of sawfish (Pristidae) in the world.  In a previous study focusing on sawfish, Nick Dulvy and fellow researchers reported that the group, which can occupy marine, brackish, and fresh water habitats at different stages in their life cycle, are probably “the world’s most imperilled marine fishes”.  Three of the five species – smalltooth sawfish (Pristis pectinata), largetooth sawfish (Pristis pristis), and green sawfish (Pristis zijsron) are classified on the IUCN Red List as critically endangered.  The remaining two species – narrow sawfish (Anoxypristis cuspidate), and dwarf sawfish (Pristis clavata) are classified as endangered.   Out of the five species of sawfish, only the smalltooth is not found in Australian waters.  More so, northern Australia is home to “some of the few remaining viable sawfish populations” in the world.  Looking after these guys isn’t just important for the Australian population of sawfish, but for the global population of sawfish.  Northern Australia’s waters is in fact, globally significant.  If northern Australia’s populations decline, then the outlook is extremely bleak for these rather unusual looking fish.

One of the key steps Karen and fellow collaborators undertook was to accurately map the range of each of the sawfish species in Australia.  They had to do this themselves because only very coarse range maps had been produced from limited data.  Sounds silly doesn’t it – a seriously threatened species, and we don’t even really know where it lives.  Understanding ranges is (rather obviously) crucial for implementing effective protected areas for these guys.  After all, a protected area situated over very little or even none of their habitats is rather pointless.  The team managed to obtain a number of records of each species that they could confidently use in their analysis.  They also used the known habitat preference of each of the 4 species and maps of Australia’s land (for the freshwater habitats they use) and sea-scapes to figure out what the most likely ranges of these endangered critters are.  Of the 2,908 records of narrow sawfish, 741 records of green sawfish, 247 records of dwarf sawfish, and 470 of large sawfish, a total of 524 records were taken within a protected area.  The percentage of range protected was also low.  For their inland (freshwater) range, between ~9 and 17% had some protection designation attached.  Their marine ranges fared a little better – around 22 – 44% some protection.

But there is something else to consider.  Not all protected areas afford equal protection.  The IUCN has a range of different categories for both terrestrial and marine protected areas.  In a marine context, at the upper end you have strong protection like areas you can’t extract things from – fishing and mining is banned.  At the lower ends you have sustainable use zones, which allow (hopefully) carefully managed activities to take place.  This can include things like fishing or mining.  When you are dealing with a species – or indeed a group of species like the sawfishes that are living in a very precarious position, ideally you want the protected areas to offer them the strongest protection possible.  Alas this is not so.  Karen and colleagues maps showed that most of the protected areas (terrestrial and marine) that covered the sawfishes ranges were sustainable use zones – zones in which activities known to be a direct threat to sawfish still take place.  What’s more, the team also note that the Commonwealth Marine Reserve network may not be all it is cracked up to be, with the current Australian Government, elected in 2013, suspending the management plans for the network.  In reality, the little protection the sawfish were supposed to be afforded by the network may be significantly eroded.

There was one final issue that the team raised in their paper – that of connectivity.  It is becoming well understood by scientists (if not politicians) that marine protected areas cannot function as single isolated islands.  Many species undertake dispersal at some time or another – the larvae of sessile organisms can travel on currents to new settlement sites, for example.  Some species – like sawfishes – can travel large distances, utilizing different habitats.  An effective marine protected area may very well need to be included inside a network, and that network needs to consider how critters move around, and how in reality seemingly disconnected sites are in fact connected.  Female largetooth and dwarf sawfish for example both pup in estuaries.  Their juveniles live in freshwater and riverine habitats.  It is only when they are older that they head out into the ocean.  These seemingly disparate but essential habitats for the sawfish (and indeed many other species) has not been considered in network design.  The urgency to consider connectivity is heightened by proposals to develop hydroelectric dams in northern Australia, something that has the potential to block migrations of these critters.

In terms of size, Australia’s terrestrial and marine protected areas may be making advances in achieving targets set by the international community, but they are far from achieving any meaningful contribution towards species like sawfishes which so desperately need help.

The paper which was published in Global Ecology and Conservation has been made open access.  You can have a read of it here http://dx.doi.org/10.1016/j.gecco.2015.01.007

 

Image: Sawfish (species unknown).  Credit Simon Fraser University – University Communications/Flickr (CC BY 2.0)

Old fishing line hints at fishing levels inside no-take marine protected areas

Dealing with overfishing and destructive fishing practices are a huge issue for marine conservation and management.  Tackling this problem, and trying to repair some of the damage is no easy task.  We know that if they are done properly, no-take marine protected areas can make an impact, not only reducing habitat degradation by removing damaging fishing techniques, but also increasing the density and even the individual size of species targeted by fisheries.   The benefits these no-take zones provide can spill over to fishers too.  And that’s not just a scientist point of view either – take a look at this short (5 minute video) focusing on lobster potter Geoff Huelin who fishes around Lundy Island – the UK’s first no-take zone.

There are many factors that can make or break a no-take zone.  In the video Geoff touches on just one of those factors – policing the zone to make sure that people are abiding by the regulations.  This is important.  It’s no good having regulations to protect an area from fishing if fishing happens there anyway.  It is the action of people – not the designation itself per se, that makes an appreciable difference to marine biodiversity recovery.  Geoff tells us that for the Lundy Island no-take zone enforcement isn’t a huge challenge because the no-take zone is viewable from the shore.  There is, Geoff tells us, usually somebody watching.  But this can’t be said for all no-take zones.  It’s not just distance from the shoreline that can impact on enforcement capabilities. Lundy’s no-take is small.  Some no-take zones are huge, and very often manager’s budgets and resources are limited.  Take the Great Barrier Reef Marine Park for example, which suffers hundreds of infringements of its regulations each year.  Sure both commercial and recreational fishers who break the regulations inside the Park are successfully caught every year using a host of different surveillance techniques, but many more are likely to go unnoticed.  Getting a handle on the scale of non-compliance is the very issue explored in this recent paper by David Williamson from the ARC Centre of Excellence for Coral Reef Studies and fellow researchers.

The research team focused their efforts on several fringing coral reefs in the Great Barrier Reef Marine Park – those around the Palm Islands, the Whitsundays, and the Keppel Islands. You may have heard of these places.  Beautiful and fairly accessible from the mainland, these areas are popular with tourists and locals alike.  Although all managed by the Park authority, the fringing reefs around these Islands aren’t all no-take, and the Aboriginal people’s of the Palm Island group have fishing and hunting rights across the whole Park – including inside the no-take zones.  The researchers needed a way to estimate fishing effort inside the no-take parts of these reefs, and for this they needed some evidence… evidence in the form of derelict fishing line from hook and line fisheries.  The first thing to do was to calculate the density of derelict fishing line both inside the no-take zones and outside.  So in the water they went and surveyed the derelict line.  Some statistical analysis later, and the team had an estimate of hook and line fishing activity both in and outside no-take zones on the reefs across the three island groups.

In the Whitsundays and the Palm Island, the no-take zones that had been around for over 20 years had the lowest density of fishing line within them compared to zones established 5 years before the surveying, and ‘normal’ sites.  Interestingly no-take zones that had been established for only 5 years didn’t show any significant difference in line density when compared to ‘normal’ sites.  But fishing line is typically made from hardy stuff, and doesn’t easily break down.  The researchers note that 99% of the fishing line found had accumulated algae and sessile organisms on them, and/or become partially embedded in the reef matrix itself.  This indicates that most of the line had been there for months or even years, but ascertaining just how long is difficult.  Some of the line likely was there prior to establishment of the no-take zones but just how much… well that is a difficult question to answer.

The team did not stop with simply working out the density of fishing line though.  Around the Palm Islands the researchers used the assistance of Reef Check Australia – a citizen science organization that is heavily involved in marine monitoring – to remove derelict fishing line from both no-take zones and monitored the sites to see just how quickly fishing line accumulated in the no-take zones and in the areas outside them for some 3 years.  Here the rates of line accumulation between the no-take zones and the other cleaned ‘normal’ sites were, statistically speaking, “marginally non-significant”.  In arguably more real terms, the researchers note that the rate of fishing line that accumulated inside the cleaned no-take zones was 32.4% of that accumulated inside the ‘normal’ cleaned sites. And 32.4%, say they researchers, is worrying for a zone that is supposed to be a no-fishing area.  But what about those Aboriginal fishers that have a right to fish inside the no-take zones – couldn’t some of the line be from them?  Well yes, though the authors note that at least from personal observations not all of the no-take zones they cleaned and monitored were regularly used by Aboriginal fishers.  What all this points to, the researchers argue, is that non-compliance with no-take zones isn’t just an issue in the more remote parts of the Great Barrier Marine Park.  They also note that when assessing how effective a no-take zone is in restoring marine biodiversity, it is worth taking into account the level of non-compliance with regulations as best one can.

This paper (including an open access link to their data) was published in the open access journal PLOS ONE.  You can read it here http://dx.doi.org/10.1371/journal.pone.0114395

Image:  The Whitsundays.  Credit Richard Rydge/Flickr (CC BY-NC-ND 2.0)

The changing face of fisheries in the English Channel

This not so small ocean critter is an angelshark (Squatina squatina) – also known as a monkfish.  Back in the 19th and early 20th century the angelshark had a pretty wide distribution across Europe, and was particularly common around the coasts of the UK, Ireland, and Atlantic Iberia.  A nocturnal feeder, these guys bury themselves in sediment and lies in wait for a tasty morsel which, for the angelshark, includes skates, flatfish, and (as once recorded) cormorants.  Unfortunately, being a demersal species (living on or near the seabed) they are quite vulnerable to being caught as bycatch in fishing gear like trawls, and bottom lines.  Unfortunately for the angelshark, they are also quite a tasty species, so they have also been deliberately targeted by fishers.  Slow growing, and producing relatively few offspring, angelshark numbers plummeted, and today it is largely absent from many of the waters it once inhabited.  The numbers of angelshark is now so low that the species is listed as critically endangered on the International Union for Conservation of Nature Red List.

There seems to be a somewhat predictable pattern to fisheries exploitation.  First, as catches declined and technology improved, we responded by moving further out to sea, into deeper grounds, and targeting new species.  Second, we tend to target predators first then, as the catch of those guys decline, move our focus onto different species lower down the food web.  The concept of “fishing down marine food webs” was first introduced by Daniel Pauly back in 1998.  Daniel used global catch data to infer that a decline in the mean trophic level of the species (an average of how far up the food chain a species is) being caught directly related to what was actually in the oceans.  In other words we are catching fewer predators because there are fewer in the oceans.  Of course the situation is much more complex than that, and there may be other reasons for changes in trophic catch levels such as regulation changes, as highlighted in a later paper by Trevor A Branch of the University of Washington and a team of collaborators.  Whatever the reasons for the declines, Pauly’s findings have been mirrored by many other papers that focus on commercial fishery catches at regional scales. Most recently, Carlotta Molfese and Janson Hall-Spence of Plymouth University, and Doug Beare of WorldFish  have cast an eye over commercial fisheries data from the English Channel, and  assessed how catches from the area have declined since the early 20th century. Continue reading The changing face of fisheries in the English Channel

Multi-tasking underwater

Often when I say to people I do underwater biodiversity/habitat surveys, they have an image of glorious tropical seas, great visibility, and general ohhing and ahhing at the beautiful marine critters. The reality is somewhat different (especially when you’re not in tropical waters!).

A small team of intrepid divers are currently undertaking maerl surveys at an offshore reef, just off the coast of Jersey (Channel Islands).  Maerl is a hard red seaweed, that forms little blobs.  It’s a super important habitat for our smaller ocean brethren, and super slow growing too.  On this particular survey, my job was to conduct a general habitat and species survey of the site, and keep hold of the SMB – basically and inflatable sausage attached to the end of the line you can see me holding that sits on the surface of the sea so we can be spotted.  You can see that the visibility wasn’t that great, but what you can’t see is the current that was trying to take me one direction, whilst the wind was pulling the SMB the other.  This is why I’m kneeling on the seabed so I could make some notes on the board I am holding, whilst also making sure I don’t let go of the SMB!

Image: Taken by Kevin McIlwee/Jersey Seasearch