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?
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
This rather interesting looking chap is a holothurian – or as it’s more commonly known, a sea cucumber. There are some 1,250 species of holothurians, most of which scavenge on whatever they find on the sea floor. This rather unfussy diet has severed this group well- you can find holothurians across all oceans, from the deep sea through to shallow coastal waters.
And if you type ‘sea cucumber’ into Google, it will give you this nutritional information….
Amount per 100 grams
Total Fat 0.4 g
Total Carbohydrate 0 g
Protein 13 g
Vitamin A 6%^
^ % daily value
Sea cucumber fisheries and aquaculture have long formed part of a subsistence diet for island and coastal communities. They have also become a luxury food item in one country in particular….China. Statistic from the Food and Agriculture Organization (FAO) indicate that between 2000 and 2009, Africa, Asia, and Oceania exported some 100,000 tonnes of dried sea cucumbers – most of which ended up in China. Overfishing is rife, with an estimated 70% of tropical sea cucumber ﬁsheries classified as fully exploited, over-exploited or depleted^^. Most of these fisheries come from nations which lack the financial means to manage their fisheries as well as they could be. Most, but not all – such as the fishery in Australia. And not just anywhere in Australia – in the Great Barrier Reef Marine Park. This might sound a little odd, but the Great Barrier Reef Marine Park is a multiple-use park. Many different activities occur on the reef, but they are carefully managed.
Or at least they should be…right? Continue reading An unsustainable fishery on the Great Barrier Reef
Check out the size of that sponge!
Seriously, its a sponge, aptly named the “Giant barrel”. But as awesome as this sponge is to look at, its not so awesome if your a coral. Research by Joe Pawlik and colleagues released this week suggests that overfishing of fish that love to tuck in to a bit of sponge means sponges are taking over on some coral reefs. There’s a nice overview of the paper or alternatively if you fancy reading the paper yourself you can – it’s open access!
Image: The giant barrel sponge taken by the paper author Joe Pawlik, UNC