Fisheries Resources

Question: Write an essay about the fisheries resources. Answer: Fisheries Resources Japan is a hotbed of earthquakes experiencing at least 300 earthquakes by the day. Based on recorded history, the country experiences, in every 30 years, a minimum of one earthquake with the magnitude of 8 and above. The active plates which are spread all over the country plus the oceanic and continental plates are to blame for this occurrence. Tsunamis tend to be generated during some of these earthquakes, case in point, the Tohoku Earthquake, which caused tremendous destruction to the seawalls and the fisheries resources. The seagrass bed communities have experienced some not so subtle changes as a result of the chaos created by these tsunamis (Miura, Sasaki, Chiba, 2012). A succinct overview of the period prior to the Tohoku earthquake points to a community that was dependent on fish products as their major protein source. On a larger scale, there has been a worldwide decline in the supply of fish products. The peak of 24 million tons has since been brought down to 20 million tons (Miura, Sasaki, Chiba, 2012). Japan has always been a giant in the field of fishing hitting 10 million tons of fish caught. This is no longer the case as 4 million tons is being celebrated as the highest figure. The trend is worrying. Another fact worthy of noting is, even though a decrease in supply should cause an increase in demand thereby an upward shift in prices, the prices of seafood seems to have remained constant. The Mongoku-ura bay area has seen a steady decrease in the number of fisherman by an estimated 60% (Miura, Sasaki, Chiba, 2012). People have resorted to other forms of income generation methods, oblivious of the potential of the fish industry. The need to increase their efforts in order to guarantee a big enough catch has discouraged many men, who over the years have seen, in other industries, less cumbersome methods of income generation. There are no incentives to engage in fishing due to the destruction of the fisheries resources by the tsunamis. The land subsidence that went as high as 1 meter because of the earthquake led to the disappearance of the seagrass beds that was mainly constituted by Zostera sp (Rogers, Kimbro, 2015). The effect of the disappearance to the aquatic life was overwhelming, and there is no understating its negative impact on the fishing industry. The same community that still had to deal with the massive destruction on their property and loss of their friends and families could not stomach such heavy blows. Nobody blames them for giving less attention to rebuilding their fisheries resources (Rogers, Kimbro, 2015). A radical environmentalist would argue that the changes in the seagrass beds due to natural forces and the eventual reduction of the dependence on fisheries resources was an advantage because it ensured survival of endangered aquatic life. One has to be a radical to make such arguments. Protection of species against extinction can be exercised through other means that would not affect the tastes and preferences of an entire community. The community has had to look for other sources of protein that have been known to create worse disturbance to the carbon footprint and vegetation on land. The level of destruction to the environment that goes into enjoying a kilogram of beef is worse than that which goes into enjoying a sushi dinner. Let that sink in for a minute. Short answer questions Discuss why high fisheries productivity is often found adjacent to the western sides of continents. List 2 such locations Down-welling and upwelling affect both the biological productivity and the temperature of the sea surface. Since upwelling is mostly common along the western sides of the continents, and because upwelling supports seagrass beds by generating favorable temperatures for aquatic life like planktons, fishes are more likely to survive on the western sides hence high productivity. Examples of such locations include Chile and Peru. For THREE marine finfish families that are major world fisheries, describe their Family and common name, distribution and where they are mostly caught, key aspects of their biology (e.g., open water pelagics, sex changers etc.), and capture methods. Black sea bass scientific is Centropristis striata, they are most commonly caught in the USA along Atlantic coastal waters with hooks. They are protogynous hermaphrodites. Pacific Cod scientific name is protogynous hermaphrodites, most commonly trawl-caught in the Pacific Ocean. They have an average lifespan of 9 years Tilapia Scientific name is Oreochromis spp., it is of an African original and is caught using fishing nets. They can reach the age of harvesting within ten months, making them very fast growers. The diagram below shows a yield curve for a fishery, intersected by a cost line (as fishing effort increases, so costs rise linearly in this example). Reproduce the diagram in your answer book, and show that "maximum economic yield, MEV" is less than "maximum sustained yield, MSV". How would this be different if a high-capital item like a large fishing vessel is purchased? When a high-capital item like a large fishing vessel is purchased, MEV would no longer be less than MSV in the short run. Describe 2 methods each of estimating the following demographic parameters for marine fishes: Fish movement Removal Model Abundance Estimates: In order to provide an estimate for fish abundance, the model utilizes standard depletion methods. This model assumes that the efficiency during sampling is generic during all the depletion captures. Probabilistic sampling: Probability sampling happens once all doable samples are enclosed within the choice method, the probability of choice is thought, and also the choice method is random. The foremost basic sampling procedure utilized in fish population sampling is straightforward sampling, during which a pre-set variety of sampling web sites hand-picked is chosen from all probabilities. Fish individual mortality Pauly 1980: this method associates natural mortality with the growth parameters of von Bertalanffy with the mean environmental temperatures. The temperatures are measure in degrees Celsius. The assumption is that there has to be a connection between the sizes of the fish with their natural mortality. Hoenig 1983: this method is commonly used to estimate fish individual mortality among the sharks. The idea is that the highest observed age can be used to predict the individual mortality of the sharks; sharks that have lived over a longer period tend to have a slower death rate. What are some of the key attributes of a sustainable fishery? Discuss the relative merits and problems with regulatory management of fisheries (e.g., effort limits, minimum legal size limits, spatial closures) vs consumer-driven product choice (e.g., Marine Stewardship Council and Ocean wise programs). Sustainable fisheries must be harvested at rates that are sustainable. There should be no point in time when fish harvesting leads to a decline in population of fish in their habitat. In this era of overfishing, subsistence of sustainable seafood is a major conundrum. Even though humanity regards the aquatic life as a suitable rich source of nutrients, regulation is key to ensuring the existence of a symbiotic relationship between man and the aquatic life. Marine Protected Areas (MPAs) are touted as important tools for both marine biodiversity conservation and fisheries management. Discuss the following in relation to MPAs: How marine parks differ from terrestrial national parks The overarching difference is that unlike in terrestrial national parks, people are prohibited from accessing the marine parks. Steps designing a MPA The most vital thing to note is getting the licencing and ensuring that you have the goodwill of the community in which the MPA is to be located. Limitations in MPAs as fisheries management tools Most of the MPAs allow a certain level of human interaction. Some have recreational facilities like fishing, hotels, et cetera. These human interactions may cause, to a certain extent, harm to the aquatic life. How MPAs can help managing fisheries They aid in sustenance of genetic diversity, ecological systems recovery, and areas utilized for scientific referencing. Oceanographic factors can greatly influence the production of fisheries. In particular, local processes can affect fisheries. Define the following (diagram) and discuss in relation to fish productivity or migration Western Boundary Currents (Eg EAC) They are deep, fast, warm, and narrow currents that flow on the ocean basins west side. They affect the circulation of nutrients and thus the migration of fishes. Local upwelling This is the process through which deep and cold waters rise approaching the surface. Areas that experience local upwelling tend to have a high population of fish since such areas have the right temperature for the survival of vegetation that the fishes heavily depend upon. Discuss both the dispersal capabilities of marine fish larvae, and some of the different modes of spawning of marine fishes, and how these are relevant to managing marine fish resources. Include specific examples. Marine fish larvae do not consume the same food as the adults thereby reducing competition among the two different groups within the same species. Some species, like pelagic larvae, can disperse over very long distances. This ensures that they colonize new territories to avoid the stressing of a particular territory for the same resources. The larvae, especially the long pelagic ones, have the capabilities to break the cycle of the parasites that attack them. Some of the modes of spawning include mouth brooders that yield juveniles or demersal post-larvae e.g. catfish, demersal eggs which yield pelagic larvae e.g. triggerfish, demersal eggs which yield juveniles or demersal post-larvae e.g. toadfishes. What life history attributes of a marine fish species would suggest that it is vulnerable to overfishing? Why? The decline in population of the large predator fishes point to the possibility that they are more susceptible to overfishing. These species have a large body size, and take a lot of time to mature and reproduce. Moreover, their parents need to invest a lot of time caring for their offspring. They also have a long life-span and averagely high trophic levels. Describe the operation of the Sydney Fish Market, specifically The Dutch auction method of fish sales During the Dutch auction, the auctioneer first asks for a high price for the product the crowd is bidding for and hen keeps on lowering it until someone in the crowd is interested in purchasing the product. Which products are not sold this way and why? Fish that are hard to catch, they fixed prices. What happens to fish that aren't sold on the day They remain frozen References Blaxter, J. H. (Ed.). (2012). The Early Life History of Fish: The Proceedings of an International Symposium Held at the Dunstaffnage Marine Research Laboratory of the Scottish Marine Biological Association at Oban, Scotland, from May 1723, 1973. Springer Science Business Media. 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