Kayak Fisherman Ireland

Asian Invasion

There has been an invasion of Ireland. We have always seen our fair share of invaders, some go back many decades but many of them are a recent phenomenon. Easier methods of international travel, a taste for the ‘exotic’ and an attitude that either doesn’t care or thinks they know best have all culminated in the last couple of decades to bombard Ireland with one invasion after the next. I am talking about the impact that invasive species, particularly aquatic, and the impacts that they could hypothetically be responsible for on our fair shores. As well as that, I hope to have a look at some of the measures that have been put in place or that should be put in place to try to halt the spread of these very real threats to out biodiversity.

Chub were a species high up on the ‘most wanted’ list of those that endeavour to keep species that did not originate here from getting a foothold and flourishing. Roach are an invasive species, unpalatable as it may sound to some, as are dace. It seems that roach have been here forever but that is not the case. Roach were first introduced to Ireland by pike anglers in the south of the country in the latter part of the 1800’s. They were brought in as livebaits and the leftovers were introduced to our waterways where they very rapidly multiplied, colonised and spread their range. From a small beginning of probably only a couple of dozen individuals they have gone on to become a species that occupies bodies of freshwater in every county of the country. Their spread has been nothing short of remarkable, aided by a relative hardiness that allows them to live comfortably within a wide range of water types and chemical makeup. They possess an adaptability that allows them to flourish and a short maturation period allowing them to replenish numbers very rapidly. And there is also the willingness of some anglers to transport them live as bait.

the Asian clams are already taking a foothold in the ShannonAlthough only here for little over a century they have become a common sight in Ireland and there are both advantages and disadvantages to having them here. I think the disadvantages outweigh the advantages but everybody is entitled to their own opinion. Some love the presence of roach and they are seen as a filler species for matchmen to aggregate larger bags at weigh ins, they give anglers a realistic target during the cooler months of the year, they are another species to target along with which comes a range of methods and intricacies that will be used to tempt them, trotting a float with a centrepin amongst the finest of them all. Being a shoal fish they represent a mass of small mouths that eat their way through the phytoplankton, zooplankton and invertebrates that our indigenous fish always fed on. The fact that they are cyprinids means that they will cross breed with others and has led to the decline of bream and rudd stocks in favour of hybrids. Indeed, waters in which a true rudd can be found are on a steady decline.

The impact of roach on the Irish fishing and biodiversity scene cannot yet be fully assessed and understood, they just have not been here long enough to assess whether they will find a niche in Irish habitats and whether their contribution to the Irish landscape is a positive one or a negative one. I think in time we will point to the latter but it is far too early to tell. All that is certain is the structure and composition of our aquatic environment has utterly changed since their introduction and they have affected each and every one of the indigenous inhabitants, sometimes for better but more often for worse. Every invader that finds its way into our freshwater systems has an impact and only time will tell us if they are devastating. Dace will fit into the same thread as will any other non-indigenous species that any self-styled Einstein decides to bring in here in his bucket.

One such case of a Clever Dick introducing species into Irish waters was uncovered in the River Barrow in 2010. For reasons unbeknown other than to the fool that introduced them, Asian clams found their way into St. Mullins. I do not claim to be an expert in Asian clams, Corbicula fluminea. I can tell you that they are a small, freshwater bivalve. They reach maturity at approximately four years old and they breed prolifically at this stage. They like to adhere themselves to solid structure on the bed of the river or lake and, being bivalves, they are filter feeders. They feed on phytoplankton and zooplankton, colonies filtering vast quantities of plankton to the detriment of native fish fry and invertebrates. The dense colonies that are formed by them also create a barrier to species that like to spawn in the substrate, potential spawning sites for shad, for example, running the risk of being overrun altogether. All of this information can be found freely and easily online and I am prepared to admit that this is the extent of the knowledge I possess on the species; that which can be found relatively easily.

Asian clams starting to carpet the substrate at the hot water stretchWhat does impress me about invasive species is the efficiency and speed that some of them can adapt to their new environment. It has been speculated that since the 17th century, invasive species have contributed towards over forty percent of all known animal extinctions. This is a statement that should make anybody who cares about our indigenous species and biodiversity sit up and pay attention. This is a figure that should make every angler, nature lover and enjoyer of the countryside want to know what the effects of invasive species are, where they come from and, most importantly, how we can deal with them. With this in mind one would assume that after being discovered in the River Barrow nearly five years ago that we should have a better understanding of them at this stage. A feasible and valid assumption but one that is proving to be false after a discovery made only a few weeks ago.

Some weeks ago there was a discovery of Asian clams made in the ‘hot water’ stretch at Lanesborough. This particular area of the Shannon is famous as a stretch of river with artificially high temperatures due to the warm water discharge from the adjacent power station. Four weeks to the day (at the time of writing) and the only action taken by any of the State organisations is that Inland Fisheries Ireland have placed ‘No Fishing’ signage around the area. There is more than a possibility that the Asian clams found their way into the Shannon having being transported there from the Barrow, most likely on a keepnet. I speculate but if I were a gambling man I would be prepared to stake my kayak on the outcome! Placing ‘No Fishing’ signs is a logical first step; try to limit the amount of anglers allowing their gear to come into contact with this easily transferred species and we might go some way to containing this outbreak. Four weeks later we still await the second step. In the meantime the new invader is free to work its way downstream to spread and carpet Lough Ree and the Lower Shannon.

With various State groups claiming to have Irish aquatic biodiversity’s best interests at heart, Inland Fisheries Ireland, National Parks and Wildlife Services and Waterways Ireland to name but a few, the lack of tangible response to this problem is alarming, eye opening and very frustrating. The clear absence of a contingency plan jumps right at you. Surely, if it were known that these clams had claimed a section of the Barrow and that they are easily transferred to other waters on fishing equipment then somebody must have had the vision to see that they would find their way into other waters? Surely even the very short-sighted could identify the potential disaster in the making and come up with a contingency plan accordingly. The inaction demonstrated proclaims that this is not the case. Incredible and another example to add to the list that can be attributed to a unique case that you could find ‘only in Ireland’.  This distinct lack of direction does not bode well for the future of Lanesborough, indeed I fear it may already be too late to remove the threat this invasive filter feeder promotes. A clear contingency plan for the inevitable that is acted upon immediately is the best approach for any invasive species.

Apart from the signs, there have been a few officials in attendance to photograph the offending invaders, presumably to bring them to discuss at length at meetings. Only last Friday I heard a prominent fisheries official giving an interview on the radio about invasive species. He eloquently explained the threats that they pose and listed a few of the usual suspects. When mentioning Lanesborough he was at pains to say that for the last few years his team had been very busy working on the Asian clams. When pressed further he could elaborate no more except to repeat his mantra that they had been very busy but without specifics it would be easy to disregard these assurances. Action sorts out problems on the ground, not photos, meetings or radio interviews. The worrying lack of any meaningful action to tackle this scourge at Lanesborough means that any work now implemented will surely be a case of shutting the stable door after the horse has bolted.

set up your own 'dipping station'If State agencies charged with protecting our biodiversity cannot carry out their mandate, what are anglers to do? I feel that it is the responsibility of the angler to ensure that their own gear is clean before moving it to another water. I am firmly of the opinion that there is nobody to blame for what has happened in Lanesborough other than anglers. The lack of action upon the discovery of Asian clams here is jaw dropping but the fact that they got there rests squarely with anglers. I have heard anglers mention that IFI should provide disinfecting ‘dip stations’ for nets at all major fishing venues. I disagree with the implementation of a policy like this. I feel that State funds could be better spent addressing poaching and pollution issues than on the costly installations of disinfectant baths that will probably be vandalised.

If you have the reasoning and financial means to drive around the country coarse fishing then you have the reasoning and financial means to set up a dip station for nets and waders at home. Aquatic Virkon disinfectant will do the job perfectly and will not cost more than a couple of tubs of bait. Just add water to set up a dip station in an old half barrel in a corner of the shed, follow the manufacturer’s guidelines for mixing and you can be safe in the knowledge that you are doing your bit for biodiversity in Ireland. Invasive species, especially those that target the smallest and most fundamental aspects of food webs need to be eradicated or future generations will pay the price for our negligence.

I just hope that as a nation we are better prepared for the Ebola virus……..

 

Poaching and Pollution

Recent events have seen the posting of videos of coarse fish bye-laws being blatantly disregarded to Inland Fisheries Ireland’s Facebook page. The response was to remove the offending videos and to encourage anglers to report all poaching and pollution incidents to 1890 3474 24; a ‘hotline’ that is manned 24 hours a day for this sole purpose. Sounds great until you hear some of the feedback. It has been the experience of me and others who have called this number to be greeted with no response. Only today a friend tried the number to report the illegal killing of pike to have the call ring out. The National Parks and Wildlife Service are just as difficult to get a hold of. Have staffing cutbacks reduced numbers to a point where concerned members of the public do not even get a response when reporting some potentially very worrying incidents? In theory a 24 hour poaching and pollution hotline is a great idea but who do we call when the reports are unanswered more often than not?

By Gary Robinson

a fully functional 24 hour hotline or an exercise in window dressing?

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