County’s Fish Not Out of Clean Water

Enjoying a day off from his roofing job, Jim Rosewitz settled in, cast his line into Mile Square Regional Park’s south lake and pulled out a one-pound catfish. A good start, but hardly enough to share.

“Sometimes, I have a big fish fry for the whole neighborhood,” said Rosewitz, who frequents the Fountain Valley lake around the dates it is stocked with hundreds of catfish.

He doesn’t worry much about the water quality, even though 150 ducks died this summer after contracting avian botulism--a bacterial illness--at the park’s nearby north lake. “Most of what I’m going to catch,” he said, “came out of the truck yesterday, so how much can get into their system?”

Rosewitz--and other anglers who eat what they catch in Orange County’s 19 major man-made fishing lakes--can rest easy, say state Department of Fish and Game biologist Diego Busatto and other water quality experts.

“If we have any doubt about the water source, then we don’t put fish in,” said Busatto, whose department stocks eight county lakes. “We don’t want anyone to get sick.”

Chances that someone would become ill from eating fish caught in local lakes are nearly nil, he said. The only major concern would be from eating long-time resident fish that had high levels of toxins such as heavy metals, arsenic or DDT in their systems, and the state Environmental Protection Agency routinely tests for such substances.

The quality of water in local lakes is good, Busatto said, and the best evidence is the thriving fisheries in Orange County lakes maintained by a variety of public agencies and private businesses.

Wilderness lakes don’t need much upkeep; nature takes care of the details. But maintaining wildlife in an artificial lake can be tricky. And nearly every lake in Southern California is man-made, designed to improve on the area’s arid terrain.

“Lakes aren’t simple,” said Christine Hanson, an Orange County environmental resource specialist who oversees lakes in eight county regional parks. “They are very complex biological systems, and you try for everything to be in balance.”

Monitoring water temperature, oxygen levels and other benchmarks that indicate when something is amiss also protects sizable investments.

The state spends more than $200,000 each year to plant catfish in urban lakes in Orange and Los Angeles counties. And private concessionaires spend even more. At Irvine Lake, more than 100,000 anglers turn out each year and pay $10-$15 to fish on the privately run lake in the foothills of the Santa Ana Mountains. A greater number pay to fish at the Santa Ana River Lakes. Each of the private operations stocks hundreds of thousands of pounds of fish annually.

In cold months, trout are the fish to catch--the season opened last Thursday at Santa Ana River Lakes and opens Friday at Irvine Lake. Most local anglers set their sights on catfish during warm months, and the lakes have some behemoths: The record catfish catch at Irvine Lake is 89.6 pounds.

Sunfish, bluegill and crappie are also plentiful, and many lakes have largemouth bass. Most anglers stick to the major fishing lakes, but you can bet people will drop their lines just about anywhere water collects in significant volume, be it city lakes, flood-control basins or homeowners association ponds.

For the most part Orange County inland waters support a robust fishery, but occasionally a lake loses its balance and fish suffer. Several times in the last 2 1/2 years, large numbers of fish have floated to the surface of county lakes:

* More than 100 catfish and carp died at a Lake Forest pond in September after application of a chemical to kill algae. A smaller fish kill happened in June at the one-acre pond.

* At Laguna Lake in Fullerton, nearly 100 fish died last year. Fish are struggling to survive in the 84-year-old, seven-acre lake because runoff has cut its depth from 15-20 feet to as little as four or five feet. A $2-million restoration project is planned.

* At Santa Ana River Lakes in the spring of 1998, heavy runoff from El Nino rains that had especially high levels of organic material--mainly cattle droppings from Inland Empire dairy farms--killed so many fish that operators of the 100-acre fishing lakes couldn’t count them all.

In each case, the cause of death was the same: lack of oxygen. The biology is simple. Fish require oxygenated water and healthy lakes have that in abundance. Oxygen is absorbed into water through contact with surface air or photosynthesis by plants in the water.

Aquatic plants are especially prolific oxygen producers on sunny days, but at night they can have a reverse effect and can deplete oxygen levels if they are too plentiful. That’s when fish kills happen.

“Usually at dawn, all the fish are gasping on the surface for air,” Busatto said.

The more organic nutrients in the water--feces from aquatic birds and fertilizer runoff, for example--the greater the growth of plants and algae. Too much of either can be deadly for fish.

But using chemicals to solve problems, such as unsightly algae blooms, can backfire, Busatto said.

“Somebody comes in and says, ‘Oh, we have too much algae,’ ” Busatto said. “And they put several gallons of chemical in and they kill everything.”

The chemical actually kills the algae, not the fish, but decomposing organic matter sucks up even more oxygen, and fish suffocate.

To promote oxygenation, most of the lakes maintained by the county have aeration systems. One was installed a year ago in the nine-acre lake in Mason Regional Park in Irvine, where reclaimed waste water with high nutrient and ammonia levels proved toxic.

“We were having fish kill after fish kill,” Hanson said. “We finally said, ‘That’s it, don’t stock [it].’ ”

Since then, water quality has improved enough that this month the lake will be stocked for the first time since 1991.

Once or twice a month, Hanson takes readings of water temperature, dissolved oxygen level, conductivity and pH level at county lakes. If necessary, she calls for application of algicides and herbicides to thin aquatic weeds.

Chemicals are used more rarely in larger, deeper lakes such as Lake Mission Viejo, Orange County’s second-largest body of water that covers 125 acres of surface area and is 67 feet deep at its deepest point.

Lake Mission Viejo is a special case for other reasons. No other Orange County lake employs a full-time biologist to monitor the water and the health of fauna and flora.

Leaning over the side of a pontoon boat in the middle of Lake Mission Viejo recently, biologist Tom Buckowski lowered equipment to test the oxygen level.

Despite ripples whipped up by a cold afternoon wind, he could still see the silver sensor after it had plunged nearly 30 feet below the surface. As he played out the cable, Buckowski talked about misconceptions about the lake, which is clear as some in the High Sierra.

“People are always asking me,” he said, “ ‘What are you putting in the lake to make it look so clear?’ ”

The answer: virtually nothing.

The key to Lake Mission Viejo’s crystal clarity is what doesn’t go in the water. By design, very little runoff reaches the private lake, making it a popular swimming and fishing hole for the 23,000-member lake association.

“Every time someone asks me,” Buckowski said, “is this an artificial or a natural lake? I have to back up and say it’s man-made in origin but everything going on inside the lake now is natural.”

One way to help nature and improve fish habitat is to encourage the growth of aquatic vegetation that pulls nutrients from the water. It’s a balancing act: too much vegetation can become a nuisance, tangling fishing lines, or propellers and anchors of boats. But properly managed, plants can be beneficial.

“It’s the cheapest way to clean water,” said Busatto of Fish and Game. His favorite comparison is two lakes less than a half mile apart at El Dorado Park in Long Beach.

One has no plant life and chemicals are used to fight algae that recently turned the lake a brilliant neon green. The other has plentiful vegetation on one end of the lake and a pumping system that filters water through the marshy area.

“The tendency is to try to find a solution inside a bottle,” he said, “but usually the best way to do it is to let nature take its course.”

Algicides and herbicides are not even an option at lakes that are used for drinking water such as Irvine Lake and the Santa Ana River Lakes, Orange County’s most popular pay-to-fish spots.

Irvine Lake has an aeration system near the dam, but for the most part the water quality is kept up by the natural equilibrium that has settled in during its 69-year history.

“The wind that comes in through the canyon,” said Steve Miller, the lake’s general manager, “keeps the water stirred up and oxygenated and keeps the algae down.”

Fish life suffered a setback at Santa Ana River Lakes during the El Nino fish kill. But recovery was swift, said Doug Elliott, co-owner of the lake’s fishing concession. Now, the water is “great,” Elliott said, pointing out that trout are among the most environmentally sensitive fish.

“If water conditions are not proper, if the fish are impaired in any way, shape or form,” Elliott said, “they won’t bite.”

And Elliott promises the rainbow trout will be biting. In the first two weeks of the season, more than 24,000 pounds of trout will be planted.

Rosewitz, the Fountain Valley roofer, occasionally puts up the $15 or $16 to drop his line at the pay-to-fish lakes, but usually sticks to Mile Square Park, where, with his $28-a-year state fishing license, he can yank out dinner.

“I’ve got poor man’s fishing down,” he said.

It’s not the most natural of settings, amid the park’s walking paths, picnic areas and playground equipment, but that doesn’t bother Rosewitz.

He knows the fish are here in the greenish brown water: The day before, more than 300 pounds of farm-raised channel catfish were dumped in.

The stocking schedule is no secret--it’s published in newspapers, posted on the Web and can be accessed on a phone hotline.

But Rosewitz often has the lake to himself on these outings, and hopes to keep it that way.

“I shouldn’t even be telling you this,” he said. “The next time they stock it we’ll have everybody and their mother out here. Can’t you just change the name of the park?”

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

Orange County’s Major Fishing Lakes

In cold months, trout are the fish to catch--the season opens Nov. 4 at Santa Ana River Lakes and Nov. 10 at Irvine Lake. During warmer months, anglers set their sights on catfish. Sunfish, bluegill and crappie are also plentiful, and many lakes also have largemouth bass.