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COMMERCIAL FISHERIES
NEWSLINE COMMERCIAL FISHERIES NEWSLINE by Ronald E. Kinnunen Michigan State University Sea Grant Program Abstract: Advisory/extension newsletter for keeping Great Lakes commercial fishing and aquaculture industries informed of relevant regulations, events, opportunities and workshops. -------------------------------------------------------------------------------------------------- On August 11, the Wisconsin DNR confirmed that a ruffe was captured in Saxon Harbor, Wisconsin, in a gillnet fished by a WDNR employee monitoring the area for ruffe. The fish was 3.8 inches in length. Earlier in the summer, a WDNR crew had captured a suspected ruffe in Oronto Creek, adjacent to Saxon Harbor; however, the identify of that fish could not be confirmed. On August 25, a crew from the U.S. Fish and Wildlife Service captured a ruffe in Black River Harbor, Michigan, in a gillnet fished for ruffe surveillance. The fish was 3.5 inches long. This was the first confirmed sighting of ruffe in Michigan waters. Then on September 1 a ruffe was captured in the Ontonagon River. These sightings are nothing new range extensions nothing from the previous nothingmost easterly site, nothingthe Bad River, nothingWisconsin. Saxon nothingHarbor is about nothing12 miles and Black nothingRiver Harbor about nothing27 miles from the nothing Bad River. --------------------------------------------------------------------------------------------------
A challenge was made by 22 State licensed commercial fishermen in Saginaw Bay to the DNR s modification of their 1988 commercial fishing licenses. The proposed modifications included three substantive changes and one reaffirmation of existing law. The DNR s four proposed amendments to the licenses included provisions: (1) precluding commercial fishermen from harvesting fish in an area within Saginaw Bay known as the slot during a three month period every summer (from June 1 until August 31); (2) entirely precluding commercial fishing for perch in the Sand Point area after May 31, 1988; (3) entirely precluding commercial fishing for perch in the inner Saginaw Bay after December 31, 1990; and (4) precluding the commercial harvesting of crappie fish between June 1 and August 25 each year, a restriction which is already provided by statute but had not been enforced by the DNR. Following a hearing on the proposed amendments, an administrative law judge issued a Proposal for Decision, recommending that three of the amendments be upheld. The Proposal for Decision recommended upholding the closure of the slot, the closure of Sand Point to commercial perch fishing, and the summer closure of the commercial harvest of crappies. The Proposal for Decision recommended reversal of the decision to close the entire Saginaw Bay to commercial perch fishing. The Proposal for Decision and additional briefs were reviewed by the director and a decision was issued. The director rejected the administrative recommendation that Saginaw Bay remain open for commercial perch fishing and affirmed all four of the challenged amendments to the 1988 licenses. The licensees appealed the director s decision to the circuit court. Following further briefing, oral argument, and a review of the record, the circuit court affirmed the director s decision as to the slot closure, and the summer closure of commercial crappie harvesting. The circuit court reversed the director s decision as to the closure of the entire bay to commercial perch fishing and as to the closure of Sand Point to commercial perch fishing. On appeal by right, the DNR argues that the circuit court order should be reversed and the decision of the director reinstated. The only amendments at issue are those concerning the commercial fishing for perch at Sand Point and in Saginaw Bay. The licensees raise additional issues in their answering brief concerning the sufficiency of the director s decision and the availability of compensation for licensees who are affected economically by the DNR s amendments to the 1988 licenses. The licensees failed to file a cross-appeal and these issues will not be addressed. In this case, the parties stipulated that there is no biological need to restrict the taking of perch. The DNR cites a user conflict between sports fishermen and commercial fishermen, and the belief that sport fishermen would have more opportunity to catch larger perch if the commercial fishing were curtailed. However, there was evidence that a ban on commercial perch fishing in Ohio, which had been implemented in an effort to increase the size of the available perch, was unsuccessful and that commercial perch fishing was reinstated. Several witnesses testified that commercial fishing takes less than 10 percent of the total perch harvest each year. Because commercial fishermen are not allowed to harvest perch smaller than 8? inches, some witnesses testified that it was their opinion that commercial fishermen took most of the larger perch, although other witnesses contradicted this conclusion. The Saginaw Bay area is the only area in the Michigan Great Lakes where commercial perch fishing is allowed. A conservation officer testified that the commercial fishermen had always had an honor code, and that they had voluntarily reduced their fishing activities to avoid conflicts with sports fishermen. The trial court found insufficient evidence that the proposed amendment would provide better harvesting or management of perch, noting that there was no reason to believe the larger fish would ever be caught if the commercial fishermen weren t out there. The trial court also concluded that the DNR was merely attempting to support one interest over another rather than attempting better management in order to protect, preserve, harvest or utilize the fish. --------------------------------------------------------------------------------------------------
Ramada Inn in Sault Ste. Marie, Michigan has been selected as the site for the Michigan Fish Producers Association Annual Convention. The dates for the convention are January 22, 23, and 24, 1995. A block of rooms at the Ramada Inn has been reserved at a special rate. When calling for room reservations, please inform them you are attending the MFPA Convention. For room reservations call (906) 635-1523. For more information on the convention you can contact Bill Scarbrough at (906) 644- 2541. --------------------------------------------------------------------------------------------------
Spawning times of lake trout have been well documented for populations from inland lakes and the Great Lakes. Reported spawning dates are in September, October, and November. The race of lake trout referred to as the humper, found near Isle Royale in Lake Superior, and lake trout from Great Bear Lake are known to spawn in August. The latest reported dates of spawning by lake trout are in November and December in Ostego and Keuka lakes in New York State. In Lake Superior research inferred from the condition of gonads from numerous lake trout captured during 1950-1954 that spawning occurred from June to November. Earliest collection of lake trout in spawning condition was on 8 June 1953 from Isle Royale, and these fish were reported to be humpers. Historically, Lake Superior contained many morphologically distinct varieties of lake trout that occupied specific depths and spawning locations. Of these, the siscowet is distinguished by its preference for waters deeper than 80 m and by the presence of excessive fat in the flesh and viscera. Little is known about the life history of siscowets even though this form is probably one of the more abundant morphotypes of lake trout, both now and historically, in Lake Superior. This fish is generally thought to spawn in November, but a researcher in 1955 reported capturing two nearly ripe females as early as July. In early September 1992 many siscowets were captured in ripe condition north of the Apostle Islands in western Lake Superior. In 1992 Charles Bronte with the U.S. Fish and Wildlife Service began research on the life history, population dynamics, and stock delineation of siscowet lake trout in Lake Superior. Siscowet were captured with gill nets in 80-150 m of water on 23-26 April 1992 north of the Apostle Islands in western Lake Superior. Of 91 captured siscowets, one male had fully developed testes in nearly ripe condition and one female had eggs running from the vent. This observation represents the earliest dates that lake trout of any morphotype have been found in spawning or near-spawning condition. Water temperature profiles taken at each netting location in April revealed isothermal conditions at about 1.5oC from the surface to the maximum depth of 150 m. Profiles taken throughout the year at these and adjacent offshore locations revealed that hypolimnetic water temperatures were relatively stable and rarely exceeded 4.0oC at depths greater than 70 m. Environmental cues are thought to play an important role in the initiation and duration of the spawning period by lake trout. Spawning begins in the fall when surface water temperatures in temperate lakes drop to about 10oC. However, environmental conditions may have little relevance in the deep waters of Lake Superior inhabited by siscowets. In deep water, temperature, light, and turbulence remain fairly constant so that seasonal differences are minimal and the influence of short-term weather events is reduced or non-existent. The discovery of these two siscowets in spawning condition in April suggests several hypotheses: 1) these fish represent remanent spawners from the spawning period that began in fall of the previous year, 2) environmental cues are not needed to induce spawning in siscowets and spawning may take place whenever maturation of gametes is complete, or 3) these fish may be representatives of a unit stock that is segregated temporally from other stocks by spawning in the spring as opposed to the fall. Source: J. Great Lakes Res. 19(3)-1993. --------------------------------------------------------------------------------------------------
Double-crested cormorant populations in northern breeding colonies have increased dramatically during the past 10 years, in part due to the abundant food resources found in southern wintering areas, and reduced impacts of chlorinated hydrocarbon pesticides from forage fish. It can be conservatively estimated that the minimum breeding population of cormorants in North America during the late 1980s to be about 235,000 birds. The dramatic losses sustained by fish growers in the South have caused increased concerns for Northern fish producers near cormorant breeding colonies. However, cormorant impacts on the fishery industry in the North are poorly understood, and few data can be found in the literature. Fish losses due to feeding at aquaculture facilities in Mississippi alone have been estimated to exceed $3.3 million annually, and control efforts cost growers an additional $2.1 million each year. Catch rates of cormorants were 5 catfish per cormorant-hour when fish averaged 12 cm in length. However, cormorants took fingerling catfish at rates up to 28 per cormorant-hour. Based on observed feeding rates and fish consumption, 30 cormorants feeding at a single 8 ha pond stocked with 51,000 catfish/ha could halve the fish density in 30 days. The estimate of total fish losses in 1993 due to cormorant predation in eastern Lake Ontario was 2.15 million pounds. Generally, salmonids comprise a small proportion of the cormorant diet. However, a large percentage of the 1992 spring stocking of 44,000 brown trout yearlings in the Montario Point- Rays Bay area of Lake Ontario were consumed by cormorants and gulls. Losses of lake trout from a single stocking at Stony Point, New York, on 25 May 1993 was 2,623 fish, or 3.4% of the fish stocked. This estimate was made possible by the recovery of 32 coded wire tags (1 per fish) from 176 pellets collected at Little Galloo Island on 26 May 1993. Wire tags recovered from other stockings and locations indicated at least another 2,295 stocked lake trout were eaten by cormorants. It is difficult to evaluate the total impact of cormorant predation on the fishery industry in eastern Lake Ontario. For example, the fine scales and bones of salmonid yearlings may pass completely through a cormorant's digestive tract and not show up in regurgitated pellets. Habitat degradation also occurs when roosting cormorants physically damage roost trees by their weight and numbers. Also, over time the accumulation of bird excrement at these sites has been known to cause vegetation mortality. Since these birds roost over water in large numbers, accumulation of cormorant excrement would be expected to degrade water quality. --------------------------------------------------------------------------------------------------
Gulls are classified legally as migratory and are thus protected by federal and, in most cases, state laws. However, permits may be obtained from the U.S. Fish and Wildlife Service to "take" gulls for such reasons as public health (contamination of water supplies), financial loss (agricultural damage), improved aviation safety, or other damage they may cause. According to Douglas L. Parr, State Director of Wildlife Services for the U.S. Department of Agriculture - Animal Damage Control, heavy droppings by gulls on rafts, docks and boats which interferes with their use can be considered damage and permits have been issued to deal with these problems. Normally such permits are issued only after frightening techniques or physical barriers, or both, have been used correctly and determined to have been ineffective. No permits are required to undertake frightening techniques or to erect barriers against gulls. Perhaps the simplest frightening technique is the use of shellcrackers fired from a shotgun or similar pyrotechnic devices fired from a hand-held launcher. Another is the broadcast of a recorded distress call, but this requires special equipment and techniques. A Canadian environmental consultant Victor E. F. Salmine has written that in some instances, trained birds of prey and even small radio controlled planes built to look like falcons have been used. In his report, upon which this article is partly based, Solman noted that to be successful, scaring techniques require constant use by dedicated users. Scaring works, he writes, only when someone does it. On the other hand, he says, habitat modification and exclusion work all the time. Habitat modification, which involves reducing or eliminating feeding, nesting, and resting sites, and water is mainly applicable to airports, park areas, and playing fields, and is best undertaken by municipalities or other legal entities. Exclusion, however, can sometimes be accomplished by relatively simple devices. Gulls have been excluded from fish-raising ponds and garbage dumps by stringing easily visible wires on long parallel spans. The distance between wires is subject to some dispute among experts. One report indicated the wires could be as much as 80 feet apart. Another expert suggests starting with wires 20 feet apart and moving them closer if needed. The Canadian researcher M.A. McLaren found that wire spacing of 30 feet was successful over a feeding site, such as a fast-food restaurant, if the food attraction was not too great. If food was very abundant, a spacing of 15 feet between wires worked. Two other researchers in Toronto, H. Blokpoel and G.D. Tessier, found exclusion success using monofilament nylon lines widely spaced over food service areas and more closely spaced over nesting areas. Solman reports: The reason gulls rarely fly under or between fine parallel wires is not clearly understood. Other birds, including pigeons, regularly fly under and between the wires. The fine wires and lines are almost invisible at 35 feet or more and may not be easily seen by gulls as they spiral down toward a landing. The avoidance reaction when the wires are seen (by the gulls) is spectacular and may disturb the gull enough to make it avoid the wired area. Another expert pointed out that lines work for gulls because of their flight characteristics. Gulls are not precision, power fliers but instead depend more on air currents and do more soaring than species such as pigeons. The USDA s Parr points out that flash tape or mylar tape is often very effective in keeping gulls off such places as docks or rafts. It must be installed in horizontal lines and twisted to alternate the red/silver at about 16-inch intervals. Some riparians have had success with a rotating device called a Gull sweeper, used widely on boats along the east coast. The device is a long metal rod balanced on a pivot. Specially designed plastic vanes on the ends enable it to rotate in the wind. In Michigan, the initial point of contact for individuals who feel they have a major gull problem is the USDA s Doug Parr. His office is at 2043 West Maple Rapids Road, St. Johns, Michigan 48879, telephone (517) 224-9517. He is available to offer advice on how to proceed and will provide application forms and instructions to those seeking a federal depredation permit. The application, which must be accompanied by a $25 fee, is submitted to the Department of Interior U.S. Fish and Wildlife Service in Twin Cities, Minnesota. A copy of the application should be sent to Mr. Parr s office, since he may be asked to make a recommendation concerning the permit. The Michigan DNR is also consulted by the Fish and Wildlife Service before a permit is issued. If the appropriate procedures are followed, depredation permits are usually issued, Mr. Parr said. He noted that such permits are generally only issued to people with control over the property where elimination of gulls would occur; thus individuals may not acquire permits to kill gulls anywhere they want. Source: The Michigan Riparian, August 1994 --------------------------------------------------------------------------------------------------
The Food and Drug Administration s preliminary regulatory impact analysis of its Hazard Analysis Critical Control Point (HACCP) for seafood has in many cases underestimated the program costs for the proposed rule, the National Marine Fisheries Service has told the agency. NMFS, in lengthy comments to FDA, said recordkeeping costs constitute a significant cost component of compliance to any HACCP-based inspection program. These costs for the most part represent a new regulatory requirement (even though it could be argued to the contrary), and as such require increased action and associated costs to industry. It noted that the economic data developed through NMFS Model Seafood Surveillance Project (MSSP) study probably represent the broadest, most consistent and uniformly applied methodology to estimate costs of implementing a mandatory HACCP-based inspection system for the seafood industry. However, in attempting to match the MSSP findings and conclusions with the proposed FDA model, FDA tends to underestimate their proposed program s costs to industry, NMFS said, noting the differences in the two programs. The National Fisheries Institute, commenting on the regulatory analysis, said it is extremely difficult to conduct such an analysis due to the large number of unknowns to which there are no positive accurate answers. The MSSP study upon which FDA relied used firms which voluntarily implemented HACCP and often had been in the forefront of quality control, while the mandatory program will include firms which have no formalized quality systems, NFI pointed out. The estimate of benefits is difficult due primarily to the very inadequate system of determining the extent and causes of foodborne illnesses in this country, NFI continued. As to alternative options, NFI said mandating HACCP for high- risk products only has significant merit since available data show the actual causes of illness from seafood are centered in relatively few sections of the industry. However, since a major objective of implementing a new system is to provide assurances to consumers that seafood products on the market are safe and wholesome and have been processed under some form of regulation, segregation of product into two categories would negate this benefit, NFI said. --------------------------------------------------------------------------------------------------
The University of Washington School of Fisheries, National Marine Fisheries Service, Washington Sea Grant College Program, Ocean Trawl, Inc., and Wards Cove Packing Company co-sponsored an international conference on fishery management June 14-16, 1994 in Seattle. The following are very interesting summaries of Status and Trends in World Fisheries and Aquaculture which were covered at this conference. Status and Trends in World Fisheries Among the changes in world fish catch are shifts in production. In 1970 the top producers were Peru, Japan, USSR, China and United States. In 1992 the rankings shifted to China, Japan, Chile, Peru, CIS (formerly USSR) and United States. The Chinese status as highest fishery producer includes their world-leading aquaculture production. Approximately 100 million metric tons of fish were produced in 1992. About 70 percent went to food production and 30 percent to fish meal. To maintain present per capita consumption, fishery production for food must increase to 90 million metric tons and 43 million metric tons for fish meal. For world fisheries, 6 percent of the stocks are considered depleted, 16 percent overexploited, 44 percent heavily exploited, 23 percent moderately exploited, and 9 percent underexploited. Pelagic fisheries make up 24 percent of the catch and account for 5 percent of the value. The overall catch of bottom-dwelling fish is up, but the catch of valuable bottomfish is down. The highest valued fisheries are for shrimp and redfish. Fishing vessels make up 5 percent of the world gross shipping tonnage. Questions about the economics and management of fisheries include the relationship of fisheries with other natural resource-based industries, the link between the price of fish and access to fish, the number of fishing vessels, the effects of government subsidies, and the diffuse nature of fisheries. The challenge to answering these questions and improving the overall condition of fisheries requires clear objectives and better communication between fishery managers and the fishing industry. In Europe, the Common Fishery Policy established in 1993 proposes new monitoring regulations for 300,000 fishermen. Management includes intermediate- and long-term goals to improve the efficiency of the monitoring program. The intermediate goals include reducing current fishing effort if a fish population is severely overfished. The long-term goals will set optimum fishing harvest with a flexible policy reflecting the great variety of countries and fisheries active from Norway to Portugal. In North American, both Canada and the United States have been faced with similar fishery management challenges. These include overcapitalized fishing fleets, changes in fishery populations due to environmental fluctuations and the effects of fishing, market fluctuations and changes in fishery management objectives. Despite these challenges, there were 534 commercially harvested species regulated by 34 management plans in the United States. The commercial fishing industry produced 4.7 million metric tons of fish worth $3.5 billion at the dock and worth $18.8 billion in value added products. This led to approximately $38.8 billion in consumer expenditures and $7 billion in exports. In the recreational fishing industry, 17 million anglers catch about 90 thousand tons of fish during 53 million fishing trips per year. Anglers spend about $25 billion annually in pursuit of fish. For fisheries to continue to produce economic and societal benefits, changes in the structure of the fishing industry are inevitable. The speakers suggested allocation of fishing rights using quotas, decisions based on scientific information as opposed to politics, and improved scientific information as ways to improve management of fishery resources in the coming years. Trends in World Aquaculture In 1974 the Technical Advisory Committee of the World Bank assessed aquaculture. At that time aquaculture produced 4 percent of human protein consumption and 12 percent of global fishery production. In 1990 world aquaculture production was valued at $30 billion. Aquaculture production has increased in response to declining world fishery harvests, species restoration/mitigation efforts, and improved aquaculture methodologies. Production aquaculture of high value species such as shrimp and salmon is stimulated by market preferences and export incentives. Research has contributed information on breeding, nutrition, diseases and environmental issues that has increased commercial output. Some of the challenges facing aquaculture are related to the diversity of species involved in this industry. There are 34 species of fish cultured today. Research for industrial aquaculture will include standardizing breeding technologies, health management, DNA identification of hatchery populations, and cryopreservation of gametes. Cultured salmon has become one of the most significant influences in the salmon industry and now comprises 30 percent of world production. In 1989-91 huge increases in salmon production resulted in price decreases. Market development by the remaining salmon industry increased. Salmon appears to be following the poultry model with increased products on the market and mass production techniques. Another component of marine aquaculture is production of shrimp. Sustainable, ecologically sound shrimp farming must address excessive development of farms that increase the organic load of estuaries and intensify disease problems. Pollution and disease problems have led to reduced production in several major shrimp producing countries. In response to these problems, the world shrimp industry is presently in transition. Development of low flow water systems and low protein diets are changing the operation of many farms and reducing their environmental impacts. --------------------------------------------------------------------------------------------------
The Food and Drug Administration (FDA) is announcing the availability of The Seafood List. The Seafood List is a revision of the FDA Guide to Acceptable Market Names for Food Fish Sold in Interstate Commerce (The Fish List), which was developed jointly with the National Marine Fisheries Service (NMFS). It compiles existing names that are recommended or required for use in labeling seafood products in interstate commerce. In recent years there has been an increase in seafood consumption in the United States, along with increased importation of unfamiliar seafood and use of different names for the same seafood in different regions of the country. These changes have led FDA and NMFS to recognize the need for a single source of recommended or required market names for seafood sold in interstate commerce in the United States. In 1988, The Fish List was published by FDA to provide a source of names that would facilitate order in the marketplace and reduce confusion among consumers. Although this list has had significant success in achieving its goals, its usefulness has been limited by the fact that it did not address invertebrate seafood species (mollusks and crustaceans). To alleviate this problem and to update The Fish List, FDA included vertebrate and invertebrate species of seafood in its current revision. In addition, to reflect its broader coverage, FDA has renamed it The Seafood List. The Seafood List represents an extensive, although not complete, listing of seafood commonly sold in the United States. This list includes market names, scientific names, common names, and vernacular names for seafood sold in the United States. The agency advises that the listed common name or market name should be used to market seafood sold in interstate commerce. Vernacular names are included on this list for information purposes only and to encourage references to the acceptable common or market name. While a vernacular name may be used within the region where the name is commonly used, the agency discourages the use of such names. FDA notes that the use of the name outside the region where the name is commonly used may mislead consumers and cause the agency to take regulatory action. Use of the common and market names supplied in this list will promote consistency in labeling among various areas of the United States and will enhance the ability of the consumer to make informed choices among seafood products. In addition, The Seafood List will provide the industry with uniform nomenclature and assurance that the use of the listed common or market names for seafood products will be in compliance with food labeling requirements. This list will also serve as a resource document for FDA and NMFS to provide consistent advice to inquiries. The agency recommends that a manufacturer or distributor who contemplates use of a name other than the listed common or market name first consult with FDA. Such a discussion may prevent expenditure of money and effort for labeling that may mislead consumers and cause the agency to take regulatory action. --------------------------------------------------------------------------------------------------
If you have a computer and have access to the information highway, you can now retrieve Commercial Fisheries Newsline through the Aquaculture Network Information Center (AquaNIC). AquaNIC is a gateway to the world s electronic resources in aquaculture. AquaNIC is maintained at Purdue University in West Lafayette, Indiana and is supported by The Libraries of Purdue University, Purdue University Cooperative Extension Service, University of Illinois Cooperative Extension Service, the Illinois-Indiana Sea Grant Program, and the United States Dept. of Agriculture Extension Service. AquaNIC is a multi-branched system containing a wide variety of information. Most documents can either be viewed on your computer monitor, down-loaded via modem, or a copy sent to your e-mail address. AquaNIC also contains an image directory that holds hundreds of pictures, short videos, and slides in a variety of common image formats. (A long-term AquaNIC objective is on-line interactive media that can be used by Cooperative Extension Service or Sea Grant county staff.) One of AquaNIC s unique features is that it is linked to other aquaculture databases on the Internet. These links are established for you when another aquaculture database is selected. For information on how to access AquaNIC, please contact your nearest District Extension Sea Grant Agent. --------------------------------------------------------------------------------------------------
The Michigan Aquaculture Development Act is expected to be acted on by the Michigan legislature in November or December of this year. The Michigan Aquaculture Development Act was developed over the past 2? years in conjunction with the Michigan Aquaculture Advisory Committee (MAAC), which included representatives from MDA, MDNR, MSU, Michigan Sea Grant, Michigan Farm Bureau, Michigan Fish Growers Association, Michigan Bait Dealers Association, and tribal nations. The Michigan Aquaculture Development Act is proposed as new legislation establishing aquaculture as part of the Michigan agriculture industry. The purpose of the proposed act is to foster the development of an aquaculture enterprise as part of agriculture, grant them private property rights, and guarantee interstate commerce of captive aquatic species. This proposed act is absolutely essential for the growth and development of the aquaculture industry within Michigan, which has not seen the rapid growth rate observed nationally during the past decade. Those wanting more information should contact Bob Baldwin at (616) 796-2284. --------------------------------------------------------------------------------------------------
The U.S. Fish and Wildlife Service now exempts live farm-raised fish and farm-raised fish eggs from Service export requirements except for marking requirements. This action exempts exporters of live farm-raised fish and farm-raised fish eggs from import/export license requirements, designated port requirements and payment of user fees. This rule became effective on August 15, 1994. Since June 11, 1992 when Director s Order No. 48, Export of Live Farm-Raised Fish and Farm-Raised Fish Eggs was issued, the Service has determined that the exemption of live farm-raised fish and farm-raised fish eggs from Service export requirements has not significantly increased the risk that illegally taken wild fish are being exported as farm-raised. Nor have the effects of this order been detrimental to Service s fisheries management or law enforcement programs. However, concerns about the possible introduction of injurious species into this country s wild fisheries will require that the Service continue to enforce its regulations relating to the import of all fish and fish eggs. --------------------------------------------------------------------------------------------------
Raceways for the culture of fish are commonly made of concrete. Concrete is composed of cement, water, sand and stones. General purpose Portland cement is principally composed of calcium oxide (lime, 64.7%), silica oxides (21.8%), aluminum oxide (4.9%), and iron oxide (2.4%). Minor amounts of Na2O, K2O, MgO, and SO3 are also present. Concern about the possible toxicity of new concrete to cultured fish prompted a toxicity study. A series of 13 concrete raceways (1.13 m wide x 0.61 deep x 5.49 m long) were reconstructed in the spring of 1993 at the Fisheries Experiment Station at Logan, Utah. Only the head wall remained from the old raceways. The raceways had 3 to 4 months to cure before they were filled for the experiment which began on 29 August 1993. No water was added to raceways prior to the experiment. While the raceways were being filled, 30 juvenile rainbow trout (Sand Creek strain, mean weight 32 g) were stocked into each of two new raceways and two control raceways. On each of the following four days, an additional two new raceways were stocked. Flows were maintained at 39 L/min in each raceway for the duration of the experiment. All raceways began receiving water at the start of the experiment. Water quality tests were conducted according to standard methods on the first day, day 10, and day 23 when the experiment was terminated. Parameters measured included pH, temperature, dissolved oxygen, hardness and alkalinity. The latter two parameters were titrated with an accuracy of +17 mg/L using a commercial test kit. Mortality was evaluated after 96 h and at day 23 when the experiment was terminated. After 96 h or after 23 days, there were no mortalities in any of the raceways. Water quality results indicated that there were negligible differences in water quality between control and newly constructed raceways, at least among the parameters measured. It is unlikely that aluminum would be a factor since the solubility of aluminum oxide is extremely low, especially at a basic pH. The results indicate that cured concrete does not present any short-term health risks to juvenile trout, even when stocked in the very first water in a new raceway. There are currently cutthroat trout in the raceways and they are healthy. It appears that no waiting or flushing period is required before stocking fish. --------------------------------------------------------------------------------------------------
Experiments in Hungary on white mice oocytes in an embryological laboratory have led to the development of a new form of fish egg incubator. The knowledge that pike-perch eggs can be incubated out of water in a damp spray, motivated a series of experiments. A small group of researchers a geneticist, an electrical engineer and a fish biologist began investigating a practical means of fish egg incubation and hatching out of water. Their criteria were that: the new method should involve low water and energy consumption; survival should be at least equivalent to that provided by traditional incubators; sterilization should not involve malachite green, antibiotics or other banned chemicals; labor should be minimal; hatching should be at an optimal time, and the incubator should work both for freshwater and seawater fish eggs preferably for most cultured species. The first experiments used common carp eggs, and established that incubation did not require water, just moisturized air. The fertilized eggs were placed on net with a mesh of about 2/3 of the eggs diameter. Metal or plastic nets made of filamentous material proved unsuitable; hard nets were best. To increase capacity, the optimum number of eggs to be placed on the net- tray was established. In the case of carp, good results were achieved with up to 2-3 layers of eggs. Sometimes, usually in batches with low fertilization rates, infections led to mass mortality. This was mostly when moisture was over 100 per cent in air, and the water condensed in droplets on the eggs. With relative humidity lower than 99 percent the eggs were damaged through drying out, which meant precise temperature-humidity regulation was needed. After a year of experimentation, this was successfully refined. The problem of sudden infections causing high egg losses remained. A further year was spent testing several chemicals and treatments to reduce the losses. A tannic acid solution was the answer, and once the treatment was perfected, even batches of eggs with less than 10 per cent fertilization rate were free of external fungal or bacterial infections without using malachite green or antibiotics. The next step was to test the method for pelagic fish eggs, such as white amur or bighead carp. Even these fine and sensitive eggs can be hatched in air. The machine was also tested for tench, koi, amur, bighead, wels, African catfish and sterlet. Later versions of the incubator have an automatic feature for separating the egg shells and larvae after hatching. The latest, and best, variant is made from material resistant to sea water corrosion. It is programmable for different species, and has even been tested for hatching the eggs of Atlantic cod. Survival was no lower than that of the control group. The fish egg incubator uses 400 liters of water per 60 hours for the incubation of 1,000,000 carp eggs. Before marketing, the machine needs to be tested for other sea- water fish as well as salmonids, but since Hungary has no sea, this is not easy, and the company is now seeking a foundation or partner to complete the job. More information is available from: Mr. Lajos Laslo, Biochemical Laboratory Service Ltd, H-1165 Budapest, Zselyi Aladar u. 31. Hungary. Tel: +36-1-271 2602, Fax: +36-1-271 2896. --------------------------------------------------------------------------------------------------
A laboratory finding of Norwegian scientists is that fish fat also fights cancer. In their tests the reproductive ability of leukemia cells was impaired by treatment with Omega-3 fatty acid similar to that found in fish oil. Concentrated fish fat had a healing effect on skin disorders such as eczema. Researchers in Spain have concluded that regular consumption of fish can help prevent asthma. Studies are being undertaken by the Spanish Medical Society SEPAR on various groups which suffer from the disease. Similar research is also being carried out in Australia. The renowned U.K. medical journal, The Lancet, in a recent issue ran an article that raised the possibility that eating more fish could calm us down. It particularly mentions consumption of such species as herring, mackerel, salmon, sardines and sprats. A study which the article cites suggests that people with a high level of a certain type of fat called triglyceride in their blood tend to be more aggressive. Oil found in fish lowers these levels. This is due to the action of a special type of polyunsaturate, Omega-3. Dr. Ray Rice of the British Fish Foundation says that a reduction in aggression may be one more of the factors contributing to the explanation of how eating more oil-rich fish reduces the risk of heart disease. --------------------------------------------------------------------------------------------------
An appalling act of environmental vandalism, the superintendent of Yellowstone calls it. Did someone poison the grizzlies? Torch the backcountry? Worse: an eco-saboteur slipped Salvelinus namaycush into Yellowstone Lake. That s lake trout to you and me, and the reason park officials are so upset is that only cutthroat trout are native to the lake. The aliens, which can tip the fish scales at 60 pounds, compared with a measly three for cutthroat, will scarf down their indigenous cousins like bears at a fish ladder. Since osprey, grizzlies, eagles and otters dine on the shore-hugging cutthroat, and have little hope of snaring the deep-water trout, the illegal stocking threatens an ecological disaster, says Park Superintendent Robert Barbee. After anglers caught two of the non-native trout in the lake this summer, park officials figured the aliens were slipped into the lake by someone who wanted bigger fish to fry (well, catch: Yellowstone is a catch-and-release lake). This was done in a very deliberate way, says park scientist John Varley. Yellowstone has offered $10,000 for information leading to the arrest of the eco-saboteur. Meanwhile, park officials are debating whether to destroy lake-trout spawning areas or release a sterile male, ensuring that the aliens die out after this generation. Yellowstone anglers can do their bit, too: hook as many lake trout as they can. And don t throw them back. Source: Newsweek, August 29, 1994. |