Sunday, 31 October 2010

The Fall and Rise of the Eurasian Otter

When I was growing up in the 1970′s and 80′s, the Eurasian otter was scarce. Decades of pollution in the rivers of the UK and much of Europe as a whole was having a serious detrimental effect on otter survival. Being an apex predator, any pollutants were concentrated, causing organ damage, ultimately leading to premature death. Even less severe cases of pollution were probably enough to reduce the fertility of otters, which for a species that perhaps lived 3-6 years in the wild and reproduced every 18 months or so, was a serious concern. In the early 1980′s, the situation had become so bad, that the otter had disappeared from many countries in central and southern Europe and much of England and Wales too. There was a real danger that the Eurasian otter would become extinct in most of Europe. Only in Scotland, where there were populations of coastal otters and Northern Europe, were they still widespread. The only other areas in the UK, where there were still healthy (albeit small) populations, were Southwest England (mainly Devon and Cornwall) and parts of Wales and inland Scotland, particularly higher ground, where the effects of pollution were lessened.

It was during this time, that I had an ambition, or perhaps given the situation, it was more like a dream. I wanted to see an otter in the wild. Of course, not only was the otter population plummeting, but they are also largely nocturnal in most habitats, which made the chances of seeing one, pretty remote.

Fast forward to 2008 and the otter population was much more healthy, at least in the UK. Many areas had been repopulated from the west and they were slowly spreading east. I visited Scotland and was finally able to fulfill my dream of 30 years earlier. I caught sight of my first wild otter, running along one of the supports of North Kessock bridge, near Inverness, before it dived into the surf. It was around 6.30 am and bitterly cold, with frequent snow flurries, but it was worth it. My ambition was achieved, but I wanted more. I then spent hundreds of hours in the summer, observing otters in the daylight, much closer to home at Shapwick Heath. Unlike most populations, the otters on the Somerset Levels show themselves at all times of the day. It is probably in part due to the local diet, where freshwater mussels make up a large part of what they eat. One of the reasons that otters are nocturnal, is because their favoured prey items are less active then, so they can expend less energy catching them.

Over the past ten years in particular, but really since the 1990′s, the otter population has become stable and even increased slowly. However, the past has shown how precarious that recovery may be. Pollution, while lessened, still occurs and a recent incident involving paint thinner almost certainly had some effect in parts of the Somerset Levels. There is also a new threat, this time from a fluke carried by oriental fish that have escaped into the Somerset river systems and have since spread further afield. This bile fluke (Pseudamphistomum truncatum) can contribute to death and certainly debilitates infected otters. Generally, parasites are adapted not to cause serious harm to their host, it’s in their interest for the host to survive. However, the otter isn’t the natural host and as is commonly the case with accidental hosts, it causes serious harm to the otter’s internal organs.

Human activity also remains a threat to the survival of the Eurasian otter as a species. Whille pollution is lessened, in the period when the otter all but disappeared, many fish farms have sprung up. This has now become a source of potential conflict, with calls from some quarters for an otter cull. This call, has largely come about due to ignorance. Many seem to think that otters have deliberately been reintroduced by scientists and conservationist on a large scale, which simply isn’t the case. Even some individual anglers have joined the call for a cull, with some heated debates on internet forums. The fact is, the greatest cause of depleted fish stocks in rivers is human activity. If a river is able to support otters, then it is a good sign that there is some sort of balance. Otters simply are not present in high enough densities to cause depletions in fish stocks and numbers would soon decrease, if there were insufficient prey items (i.e. fish and crustaceans) to support them. Only in fish farms, where they are allowed access, are they likely to cause a problem and that problem is one that is easily overcome. Fish farms are big business and many of the fish are prized oriental carp, worth thousands of pounds, so an otter let loose in a fish farm will cause alot of damage. However, it is the responsibility of any business to protect their assets. In the case of fish farming, it is very easy to keep otters out, by using fences. Otters won’t try to force their way through an electric fence, as it would cause them discomfort. Like many predators, they will go for the easiest prey, if the fish farm isn’t otter-proof, then it will be the fish farm, but if it has adequate protection, then the otter will go elsewhere, where they won’t get a jot of electricity. Also, to put things in a bit more perspective, there are an estimated 3500-4000 otters in England and Wales, with a further 4000-4500 in Scotland (many of which are around the coasts). Their diet consists of around 90% fish and crustaceans. In comparison, the American mink has a diet of around 40% fish and crustaceans, with the rest being birds and small mammals. The mink is much smaller than the otter, so will eat less, but population estimates for the mink are around 35000 to 40000, perhaps five times as many as otters. It is therefore likely that mink account for more fish predation in total than otters, not to mention the other problems they cause to native breeding birds and small mammals, such as the water vole, which has seen an 80% drop in numbers in the period that the American mink has been at large in the British countryside.

I now have several photographs of otters, but none that I am really happy with. Otters have provided me with hours of pleasure and I hope they will continue to do so for many years to come. While the otter is a protected species, it still faces numerous threats, mostly either directly (through pollution and altered habitat) or indirectly (through realease of non-native species, such as oriental fish) caused by human activity. If the otter and the whole of the habitat each one inhabits is to survive, we have a responsibility to protect our environment. We must preserve the otter for future generations to enjoy.

Thursday, 14 October 2010

Two Images Licensed in the Last Week

It's been a successful week or so for me lately. Last week, I managed to licence one of my Bridgwater Carnival images, then yesterday, I licensed one of my kingfisher images. Purely by coincidence, I bought this month's BBC Wildlife Magazine and when I found the licence details, I thought there was a good chance, that it was part of Simon King's article on the Somerset Levels and lo and behold, there it was on page 86. Quite small and cut out and flipped, but it's always nice to get something in a well known magazine.

Monday, 11 October 2010

Autumn and Photography

Photography can be a productive time for the nature photographer. Not only do you have the autumn colours to add a dimension to landscapes, but you also have the closeup abstract of autumn colours, not to mention all the fungi that spring up, telling the story of death and rebirth. They are nature's way of recycling the old, ready for the new in Spring. Of course, they come in all shapes and sizes, from the tiny Mycena spp. to the larger polypore fungi seen on tree trunks and at their bases. Many are simply white, brown or grey, but others add their own colour to autumn, with bright reds, pinks and purples, with a few yellows and even blues and greens. The weather may not always be at its best, with many dull grey days, but even these help to enhance the colours. Even on the dullest of days, it should be easy to find something in nature to photograph.