The Future of Yellow PerchBy Judy Nugent - November 1, 2006
The current regulations are set by individual states. In Wisconsin the Lake Michigan perch season is closed from April 30 to June 16th to protect spawning fish. The daily bag limit is 5 fish a day. These restrictions sound reasonable. They are in place to protect fish while they are spawning, and low bag limits are a good idea when a population is down 90%. Few Wisconsin fishermen have a problem with the low bag limit. In the conservation hearings an overwhelming majority voted in favor of the regulations. Fishermen see the declining numbers and want to help or at least see these measures as reasonable.
In Illinois, the Lake Michigan perch season is closed in July and the daily bag limit is 15. So in early June, when fishermen in Kenosha, WI have to sit home, Illinois fishermen a few miles away in Winthrop Harbor go home with a bucket of perch. It is no wonder that many are shaking their heads. Ed Bloom of Racine, a local fisherman, says, "this is an uneven playing field." Why does Illinois have larger bag limits? In part because that it what the politicians have decided. In addition, most perch are found in the southern part of the lake. Because they are found in greater numbers, more can be taken.
Many say the best way to solve the tension is to fix the perch problem. In 1994 the Yellow Perch Task Force was created to investigate the problem and bring population numbers back up. DNR agency personnel from the four states bordering Lake Michigan plus scientists from selected universities including Michigan State University make up the group. It was important that this group start collecting data right away. Fish populations have fluctuated on such a large body of water. Changes in nutrient loading, fish stocking programs, changing food sources, exotics and fishing pressure all made past data unreliable in predicting future populations. It was essential that correct documentation and data collection start. Each group did its own sampling on the lake and found the same low numbers as Wisconsin's DNR. But why the decline?
The reason for the decline is still not fully understood. Environmental effects such as wind and wave action are thought to be part of the problem. When fertilized eggs are swept into the open lake, when they develop into the larval stage, they will find themselves in a virtual desert with little to no food. Clearer water has also led to increased predation by alewives. On top of this is the interference from exotics and competition from other organisms that feed on plankton. Even after years of research, the odds are still stacked against young perch. "What we need," says Brad Eggold DNR Lake Michigan fisheries supervisor, "is a lot of different year classes spawning at different times. Then if we get unusual weather, high winds, or a food shortage, it will only affect the population born that week. We'd still have the other year classes to help boost populations. It is all about timing and the more spawning fish we have, the bigger the window of opportunity." Pradeep Hirethota, DNR fisheries biologist, agrees saying, "we have seen more change in the last 15 years than anyone would have predicted. The one thing that is clear is the need to protect the remaining fish to give them a chance to pull off a decent year class."
Then came 2005. Members of the Task Force conducted research independently of each other, yet they all had similar results. 2005 seems to be a fantastic year class. Annual surveys of young of the year (YOY) perch using bottom trawls and beach seines in the fall are usually good indicators of the number of fish hatched in a given year. They are also a good indicator of future year class strength. In seining for YOY last fall, researchers found 39 perch per haul. This is a dramatic increase. In the past, the best year class was 1998 where they found only 18 perch per haul. Similar results were found when they used small gill nets. In the past, the previous high was 12.75 perch per 100 feet surveyed. In 2005 they found 195 per 100 feet! This is fantastic news for anyone following the perch story. Yet, it is only natural to be skeptical. Could the numbers really be that good? Eggold says, "we found perch in many locations. By doing so we make sure that we aren't just finding a small pocket of fish. Because all of the other states and researchers are finding the same thing, it gives credibility to the data. They are all seeing the '05 growth."
So what made last year such a successful year? "If we knew that, we'd have the problem solved," says Eggold. "At the very least we are seeing the benefits of the reduced bag limits. Having more fish, especially females, in the system is starting to pay off." Meanwhile, the Task Force is looking at how it might change regulations in the future. "We'd like to see 3 of the next 5 years have a strong year class. Regardless, the '05 fish will not be catchable for another year. In that time the members of the task force will be working with all of the states to find and implement regulations that work for the fishery." In the future, the Task Force may recommend a policy that is used effectively on Lake Erie. The idea would be to identify different zone and to imposed different regulations based on the zone. Instead of having one bag limit in Kenosha and a different one 10 miles away in Waukegan, IL, there would be one regulation for the zone, independent of state lines. Eggold admits that the DNR might go in this direction, but that they are years away from it. They are currently developing a Yellow Perch Decision Analysis Model to calculate how much fishing pressure the perch can take.
While this is great news, the young perch will still need to avoid predators. Yellow perch live about seven or eight years and reach sexual maturity in three to four years. In the past, studies have shown that a low population of perch can still produce a large number of eggs. Yet survival from the egg and larvae stage to the fingerling stage is poor. Typically, eggs hatch in 8 - 10 days but may take up to a month before fry emerge. If these eggs hatch in the middle of the lake where there isn't any food, they will starve, and even if they find enough food, they may never find there way back to shore where there is better cover. In the open lake the young perch are susceptible to predation by alewives and other fish who consume larval perch. Predation isn't the whole reason for poor recruitment and survival, but it is significant. The 2005 year class will need to avoid these predators for a few years before they are mature enough to spawn, yet the fact that they made it this far is very encouraging.
Until an exact cause of the decline can be determine, there is little the DNR can do but monitor the situation. Some fishermen, like Carlton Alt of Milwaukee have asked for the DNR to do supplemental stocking. However, stocking is not a viable option for several reasons. First is the cost of starting up a new stocking program. To get the size they need, the DNR would have to spend 16 cents for a 1-2 inch perch, and 30 cents for a 4 inch fish. This might not seem expensive until you look at the target numbers. The DNR would need to stock 16 million fish, obviously too expensive to consider.
The next problem is collecting all those eggs. Getting donor stock from other places would introduce a new genetic component. This would be very dangerous to stock, especially when the existing perch are already reproducing naturally. According to Eggold, this process would cause more harm than good. Getting eggs from local perch is not easy especially given the low population.
In addition, even if the scientists do understand the problem, they may not be able to reverse it. Problem species like the zebra mussel are nearly impossible to eliminate from the lake. Also, it is unlikely that there will be only one definitive answer to the problem that will be easy to fix. Even with a few good year classes, it remains to be seen just how long it will take the population to recover.
What can you do?
The best way to help this fishery is to follow the regulations and keep daily bag limits low until a healthy population is established. In addition, it is best to practice catch and release of the females. While this is a good idea, it is sometimes hard to follow. Because of increased water clarity, perch are found in deeper waters. When you catch a perch that is in 40 feet of water and reel it up to your boat, the swim bladder of the fish enlarges. The phenomenon is similar to the "bends" in humans. The water pressure changes and it is hard for the fish to adapt. While most are able to swim back down once released, others remain near the surface and are easy prey for seagulls. To effectively practice catch and release, monitor your depth to maximize the chance that the released perch will survive.
Another way to help the perch is to get involved. Conservation groups like Perch America are dedicated to protecting the perch and take an active political role to secure appropriate state regulations. President John Hindahl says, "we fought hard to get the netting stopped in Illinois and Indiana. Since it stopped we've had a good year in '98 and '05. We're also big on fighting exotics like the Gobies. We want to see a law where all large ships need to sterilize their ballast. It is these ships that are brining in most of the exotics." Grass roots activism together with scientific research is the best way to preserve our perch fishing heritage.
Hopefully the scientists in the Yellow Perch Task Force can balance science and harvesting to pull this popular fish out of its tailspin and help produce a few good year classes in the near future. The Friday night perch fry should not become a story we tell our grandchildren. Luckily the 2005 year class will help to sustain the perch population for a few years to come, but there is still more to do.