Triploid Grass Carp

The grass carp, also known as the white amur, is a vegetarian fish native to the Amur River in Asia. Because this fish feeds on aquatic plants, it can be used as a biological tool to control nuisance aquatic plant growth.

In some situations, sterile grass carp may be permitted for introduction into Washington waters. Permits are most readily obtained if the lake or pond is privately owned, has no inlet or outlet, and is fairly small. The objective of using grass carp to control aquatic plant growth is to end up with a lake that has about 20 to 40 percent plant cover, not a lake devoid of plants. In practice in Washington, grass carp often fail to control the plants or all the submersed plants are eliminated from the waterbody. 

The Washington Department of Fish and Wildlife determines the appropriate stocking rate for each waterbody when they issue the grass carp stocking permit. Stocking rates for Washington lakes generally range from 9 up-to 25 eight- to eleven-inch fish per vegetated acre. This number will depend on the amount and type of plants in the lake as well as spring and summer water temperatures. However, Fish and Wildlife generally err on the side of stocking the least amount of grass carp as possible. To prevent stocked grass carp from migrating out of the lake and into streams and rivers, all inlets and outlets to the pond or lake must be screened. For this reason, residents on waterbodies that support a salmon or steelhead run are rarely allowed to stock grass carp into these systems.

Once grass carp are stocked in a lake, it may take from two to five years for them to control nuisance plants. Survival rates of the fish will vary depending on factors like presence of otters, birds of prey, or fish disease. A lake will probably need restocking about every ten years. 

Grass carp imported into Washington must be tested to ensure that they are sterile. Because Washington does not allow fertile fish within the state, all grass carp are imported into Washington from out of state locations. Most grass carp farms are located in the southern United States where warmer weather allows for fast fish growth rates. Large shipments are transported in special trucks and small shipments arrive via air. The photograph shows the truck used to transport grass carp for Chambers Lake in Thurston County.

20 Channel catfish

The honors of being the most popular and abundant sport fish in Iowa go to the sleek and tasty channel catfish. Sometimes called “prairie trout,” channel catfish are found in nearly all of our lakes, ponds, streams and rivers. Channel catfish are, beyond a doubt, the most abundant game fish found in our streams. Studies have shown that populations of 500 to over 5,000 pounds of catfish per mile in Iowa streams are quite common. Lakes and ponds also produce excellent catfishing, and it is in these waters that the largest specimens are found. The large flood-control reservoirs contain natural populations of channel catfish; however, annual stockings of hatchery-reared fish are required to maintain the populations in small lakes and ponds.

Habitat

First, before getting into the actual fishing techniques it might be advantageous to take a look at the natural feeding habits of this species. Catfish, by and large, are omnivorous feeders with a well developed sense of smell. This simply means they consume a wide variety of food items, and the fish is most often attracted to odoriferous or “smelly” morsels of food. The single greatest determinant of catfish food preference is body size. Smaller catfish, those less than 14 inches, feed primarily on bottom-dwelling organisms, such as aquatic insect larvae and other invertebrates. As catfish grow to a larger size, their diet changes and a wider variety of food items are eaten. Fish, however, either alive or dead, make up the bulk of their forage after they reach 16 inches.

The diet of channel catfish also varies with the different seasons. Some food items are more available at one time of the year than another, and channel catfish take what food is vulnerable to predation at that time. During late winter and early spring the most abundant food is a wide variety of organisms, including fish, that have succumbed to the harsh winter. These morsels, in various stages of decomposition, are consumed in large quantities by catfish. It is not unusual to find catfish stomachs gorged with decaying fish shortly after ice-out. As the water warms into late spring and summer the diet of catfish shifts continually to food items that are again most available and vulnerable. The most prevalent foods at this time of the year are aquatic and terrestrial worms, fish, frogs, crayfish, mulberries, insects and their larvae forms, elm seeds and algae. Many other items are consumed but usually make up only a small portion of the menu. Catfish food habits in the fall again change as the water cools. More fish is consumed along with aquatic invertebrates and terrestrial insects. Frogs become increasingly important for food as they move into streams before the onset of winter. Under the ice cover catfish feeding is reduced to a low level and consists mostly of dead fish that are picked up from the bottom.

Feeding Habits

Iowa is blessed with nearly 20,000 miles of interior streams that are virtually loaded with channel catfish. These streams contain the most under-utilized fisheries in the state. Low fishing pressure on these rivers is due mostly to the relatively poor access provided by public facilities and the more difficult and challenging fishing conditions presented in flowing water. For those fishermen that persevere, these streams offer some of our most unique outdoor opportunities. Whether bank fishing, wading, or fishing from a boat, Iowa rivers and their stream corridors offer an unexcelled nature experience. With few exceptions, a trip to the “old fishing hole” in any major river will usually be accompanied by solitude.

Catfish fishermen, those that are “dyed-in-the-wool,” enjoy the beauty of a stream, but they aren’t fooled by the tendency of the river to hide catfish. The experiences of these anglers over the years have shown that catfish are not evenly dispersed over the stream bottom; rather they are concentrated in certain areas, and the success in putting fish on the stringer depends on their ability to search out and find the reaches that hold fish. In fact, some of the more knowledgeable catfishermen feel that 90 percent of the fish are concentrated into 10 percent of the habitat. One of the best ways of improving your catch of catfish is by closely observing the characteristics of locations that produce fish – or likewise do not produce fish. Some careful observations and the tried and proven techniques of trial-and-error will make any angler a good stream catfisherman.

Stream Fishing

Stream habitats that concentrate fish are riffle areas just above pools, cut-banks, snags, rocks, and other submerged structures that are located in the stream. The outside edge of river bends usually has a cut-bank and deep water which hold large catfish populations. On the other hand, the inside portion of river bends always contains shallow water and sand bars with little habitat diversity, which in combination produce poor fishing. The accompanying illustration points out some of the typical catfish habitats found in an Iowa river.

Lake Fishing

Lakes also produce good channel catfish fishing, and the opportunity for this type of catfish fishing continues to improve in our public waters due to an aggressive stocking program with large fingerling fish. Stocked fish grow rapidly and to a large size. In fact, the largest catfish caught in the state each year are invariably taken from lakes and ponds. Fish caught in our man-made lakes in excess of 10 pounds are quite common.

Like catfish that inhabit rivers, lake-dwelling catfish are not evenly dispersed but concentrate into specific locations. The major cause of this concentration is the thermal and chemical stratification that is in place in Iowa lakes during the summer. Most ponds and fishing lakes stratify into three distinct thermal layers 10 to 15 feet below the surface, and water in the lower strata contains no oxygen – and consequently no fish. As a result, it is a waste of time and effort to fish in the deeper water during summer. Restrict your angling to depths above this stratification level. In many recreation lakes this depth will be posted near access points. Or if you desire, a temperature profile at the deepest point will give the definite answer of where to fish. Streams that inflow into the upper ends of lakes also have the tendency to concentrate catfish, as does submerged structure such as timber, rock protected shorelines and drop-offs. The best advice is to look for diverse habitat – the more diverse the habitat, the more attractive it is to catfish.

Baits and Other Catfishing Tips

Using the right bait is probably the most confusing part of channel catfish fishing, and there are nearly as many concoctions as there are catfishermen. Bait selection ranges from nightcrawlers, chicken blood, chicken liver, chicken or fish guts, crawdads, grasshoppers, water dogs, live and dead minnows, cut bait, and a multitude of prepared “stink” baits. The prepared baits most often have one thing in common – cheese. All of these bait preparations and many others are excellent for catfish, and all will catch fish. Selection of a bait from this lengthy list may seem difficult but in actual experience selecting bait for catfish can be made into a rather simple process.

The most important points to consider when selecting catfish bait are to determine the size of fish sought and the water temperature of the lake or river that will be fished. The rule of thumb is to use cut-bait or dead minnows for the best luck in late winter and spring-time just after ice-out. This bait is composed of half-rotten fish and should be fished when the water temperature is less than 60 degrees F. Catfish actively feed on fish flesh and other animals that die during winter and sink to the bottom. The stronger the rotten odor of bait this time of the year, the better the success. Fish in deeper portions of the lake or stream prior to ice melt; then shift your efforts to shallow water afterwards. The shallow water warms faster and attracts catfish into the near-shore reaches. Catfish can be caught under ice conditions, but feeding begins in earnest after the water temperature reaches 40 degrees F.

The keen sense of smell possessed by channel catfish make it one of the few species of game fish that can be readily caught during high stream flows in the spring, summer, and early fall. During these conditions the bona-fide catfishermen prefers to fish during periods of rising water levels. This method is common among catfishermen, but the exact reason for a feeding frenzy by the fish is not understood. Fish surely become more active during this time; however, the converse is true for falling water levels. Catfish usually become less active during falling levels and are less susceptible to the angler. During periods of stable or rising water levels nearly all baits will produce good catches of catfish. Use those baits that are most available under natural conditions.

One of the most popular catfish baits that is easy to store is prepared bait. As water temperatures warm to 70 degrees F and above, many catfish anglers switch to one of the prepared baits. This bait is most effective for pan-sized catfish during mid-summer – June, July and August. Summer is the normal period of low stream flow, and smaller streams can be fished most effectively by wading. A pair of cut-off jeans and old tennis shoes will allow you to walk directly in the stream. Catfishermen seeking larger fish during this period use large-sized baits such as dead bluegill, live chubs, water dogs, crayfish and frogs. Large catfish like a good-sized meal and the movement of these creatures will attract their attention.

Winter Fishing

Even the hardiest fishermen often neglect catfish during winter months, but ice fishermen angling for panfish are often surprised by the hefty weight of a large catfish on light tackle. This is not an uncommon occurrence during winter in lakes with good catfish populations. For the best luck fish near the bottom with minnows, small insect larvae, or cut bait and do not move the bait. A reel and heavier than normal ice fishing tackle is required to consistently land catfish through a small panfish hole in the ice.

Tackle Selection

Tackle used to fish catfish is almost as varied as the baits. Lake anglers use relatively short rods, but stream anglers seem to have the best success when using longer rods from 6 to 8 feet in length. Many even use a fly rod. The advantage to the longer rods, when stream fishing, is the reach they afford for better placement of the bait. This allows the angler to fish many good holes without casting. Just drop the line near a likely spot with no more line out than the rod length. This provides excellent control of the bait for better placement and improves the chances of hooking a fish after a natural-like presentation. Ten-pound test line is recommended over lighter weight line because the bait is fished on the bottom and often near underwater snags. Catfish fishermen have been slow to abandon braided nylon line in favor of monofilament, but this transition is now nearly complete.

The type of reel used makes little difference, but it is essential that it be in good working condition. If you are fishing for large fish, be sure to match the reel to the fish. Light duty reels are made to catch small fish and heavy duty reels have the power to land lunkers. Light tackle will catch more smaller fish but may not handle one of record class size. The thing to remember is that catfish may be in snags or heavy cover in the river and after the strike the fish may need to be “horsed” a bit.

Terminal tackle is an important consideration when setting out after “old whiskers.” The most important part of the terminal tackle is the sinker and hook. Catfisherman need not show concern about the sizes, shapes, and color of expensive lures, but hooks and sinkers, inexpensive as they are, are important. Always use the lightest weight necessary, and always use a slip sinker (two typical catfish rigs are shown in the accompanying photographs). The slip sinker rig allows a catfish to pick up the bait without feeling the weight of the sinker. With any resistance on the line whatsoever, a respectable channel cat will leave the tasty bait morsel in search of another. Always use a sharp hook. Hooks with bait holders on the shank are preferred by most anglers. Use sponges or plastic worms when fishing with one of the soft, prepared cheese baits. No matter which hook and bait you select, present it to the fish in the most natural manner, which always requires the use of a minimum amount of sinker or weight.

Hints for Better Catfish Fishing

Catfish, like all fish, are not randomly distributed, but are congregated in particular locations. Fishing success will depend on your ability to find these concentrations of fish.

Light tackle catches more fish, but heavy tackle is required in snags and structure when catching large fish.

Catfish can be caught year around.

Use dead minnows or cut-bait in the late winter and early spring when the water temperature is between 35-60 degrees F.

Use prepared cheese baits in the summer when the water temperature is above 70 degrees F.

Cheese baits are most effective on fish 10 to 16 inches in length.

Live bait is best for larger fish, those above 3 pounds.