So I meant to post about this back in July, but got…side tracked.
I realize posting about it in November is a bit late, but bear with me. I found it interesting.
Back in July, the Everglades Cooperative Invasive Species Management Area hosted a non-native fish roundup. Simply put, a tournament to catch exotic fish in South Florida. The results, along with pictures can be found here: http://www.evergladescisma.org/roundup/results.cfm
I found this whole thing interesting because of recent events here in Florida. Two winters back, Florida had near record breaking cold snaps and freezes. There were widespread snook kills and a massive die off of exotic fish, in particular, the Oscar.
The ecologist in me was happy about the exotics dying off, but the fisherman in me worried. Even for their small size, Oscars are one of my favorite fish to catch. There’s just something about tossing a fly near a fallen log, and having a fish a little larger than a bluegill, engulf it and fight 10 times as hard. So was having a large population of these exotic fish die off a good thing?
It’s hard to tell really. I’ve read papers about both Oscar’s and Mayan Cichlid’s effects on native species such as Largemouth Bass. From what I’ve read, having the exotics around hasn’t really caused much damage. Yes there is a large amount of predation on small bass by the exotics, but at the same time, big bass have an almost unlimited supply of tasty cichlids.
To add, there’s actually an exotic species that may suffer from a die off of Oscars. That species is the Butterfly Peacock Bass. Native to the Amazon in South America, the Butterfly Peacock Bass was purposefully introduced into the Florida Everglades by the state to help control Oscar and Mayan Cichlid populations. Since then, the Peacock Bass have become a major sport fish. So there’s the possibility that having a large amounts of Oscars dye off could be detrimental to the Peacock Bass.
I’ve seen a change in the amount of exotics first hand. My first encounter with these fish was in May of 2008. My dad and I stopped along the Tamiami Trail and noticed that there were -hundreds- of fish teeming around the rocks and bushes in the near by canal. At the time, we weren’t sure what they were, but we knew they weren’t native. Using worms and gold hooks, we proceeded to have a hay-day.
My next trip occurred in early August of 2008. -Something- changed in between that time. Perhaps the heat forced some of the fish into deeper water…Who knows. But they weren’t as thick as they had been in May. That’s not to say, however, that they weren’t there. We still found them, and filled the cooler.
In May of 2009 I found myself down in the Glade’s again and just like the previous year, the fish were thick. I caught close to 10 Oscars off of one sunken log at one point and this time we laid into the Peacocks as well.
Winter of 2009 was when the freezes hit.
I made it back down to the Glade’s in June of 2010. Immediately, I went to see if the exotics were still there. It took quite a bit of poking around, but I finally found them. They weren’t -nearly- as thick as they had been the year before. They were definitely few and far between. I made another trip later in the summer since I was working within 3 hours of the Glades. Once again I found the fish, but they were still lacking a bit.
Realizing that the fish were still alive, I desperately wanted to get back down there. And from everything I’d read, the BEST time to fish for them was around December or January. I made a trip down there again this past February to get in on some of the -awesome- fishing…We went just in time for a cold front.
The cichlids were all but gone. The cold had driven them into holes and deep spots, and we only saw 2 or 3 Peacock Bass the whole trip.
It, of course, was in the 70’s the following week, and I’m sure the fish were teeming once again.
I haven’t been back down there since. So reading about the exotic fish tournament was interesting. The total weight of fish they pulled in was almost 226 lbs. That may not sound like a lot, but remember, Oscars and Mayans usually weigh about 1-2 lbs. They pulled in -alot- of fish. However, I searched and couldn’t find if they’d had previous tournaments. It would be interesting to see if there was a change in the amount of fish pulled in before and after the kills.
I’m really not too worried about the exotic populations after the freezes though. From keeping Oscars in an aquarium, I know that under the right conditions, they can grow up to an inch per month. They usually max out at about 12-13 inches, so you do the math.
I’ve no doubt that the exotic fish species are there to stay. It would take more than just some cold snaps to get rid of them. I certainly look forward to the next time I can make a trip down there. Until then, I’ll just tie up flies for cichlids, and look through old pictures in anticipation.