When it comes to doing research, or problem-solving in general, I try to assume I haven’t asked the best possible question yet. This is especially so when I’m doing research in a place I’ve never been before, working on ecological questions I’m not fully familiar with (cough cough, Lough Hyne). Going from analyzing fishing as a recreational activity that exerts a pressure on the ecosystem to studying the fishes themselves has been an interesting change—I’m finding fish to be much more predictable. Of course, that doesn’t mean this type of work is easier than pure fisheries research. That fish are more overtly rational makes their behavior a bit more understandable at the surface, but that hasn’t translated to them listening to me when I explain to them how they need to cooperate for my study.
The actual study consists of conducting 50-meter band transect surveys to obtain visual counts of fishes in 5-meter stretches. A bit inexact, yes: the saying by fisheries scientist John Shepherd, “counting fish is like counting trees, except they are invisible and they keep moving” comes to mind. However, I’ve found this approach to be full of data once I include predominant bottom type and depth for each 5-meter section while separating the dominant (in numbers, not in body size) gobies from the other fishes seen. Add in some repetition to cover every combination of high water versus low water and time of day (well, morning, midday, and late day) and the questions start poking through every which way. And naturally, some of them begin to poke holes in my original plans, which I’ve learned is not necessarily a bad thing.
The goal of this project is to begin the process of assessing how fishes fit into the structure of functions of the ecosystem in Lough Hyne. Mainly, how does their presence on the benthos affect the chances of a possible urchin recovery? We’re reasonably sure there are few, if any fish that eat settled juvenile urchins, but that doesn’t mean they’ve signed some sort of hands-off treaty. In just a few surveys, I’ve seen fish sliding along the bottom, kicking up sediment and disturbing the benthos. I’ve seen them occupying the many nooks in between rocks small and large. Do these benthic fishes have any impact in permanently utilizing prime habitat, or is their residence too transient, changing between low and high tide or throughout the day? And looking from the other side: if urchins recover, could they be the ones doing the displacing by devouring the valuable algal refuges that prey fish love so much? I don’t know, but it appears these types of animals can and would coexist. So if I had to put the life savings somewhere, I’d bet the most important factor in this ecosystem equation is still out there, waiting to be noticed.
Until next time,
Until next time,