Marine Biology Exam Part IV

A Manatee Only Pleases Everything!

Pelagic catches are defined as those that are harvested from the open water. This means that the fish or other marine organisms are caught in the ocean or sea, away from the bottom or estuaries. Pelagic species are typically found in the upper layers of the water column, away from the seabed. These catches include fish like tuna, mackerel, and sardines, as well as other marine organisms like krill. Harvesting from the open water allows for a wide range of species to be caught and is often done using methods like trawling or purse seining.

Competitive exclusion refers to a situation where one species outcompetes and eliminates another species. This occurs when two species have similar resource requirements and compete for limited resources in the same ecological niche. The species that is better adapted or more efficient in utilizing the available resources will eventually outcompete and eliminate the other species. This process is a result of intense competition for resources and can lead to the exclusion of one species from the ecosystem.

Continued catches above the maximum sustainable yield will result in overfishing. This means that if the catches exceed the maximum amount that can be sustainably harvested from a fishery, it will lead to a depletion of fish stocks and disrupt the balance of the ecosystem. Overfishing can have serious consequences, including the collapse of fish populations, loss of biodiversity, and negative impacts on the livelihoods of those dependent on fishing. Therefore, it is important to manage fisheries sustainably and ensure that catches do not exceed the maximum sustainable yield.

Oil is considered a marine non-renewable source because it is formed from the remains of marine organisms, such as plankton, over millions of years. These organisms are subjected to heat and pressure, causing them to decompose and transform into oil. Once extracted, oil cannot be replenished within a human timescale, making it a finite resource. Additionally, oil extraction and its use can have detrimental effects on marine ecosystems, further highlighting its non-renewable nature.

A group of mussels of a particular type living together on a rocky beach is an example of a population. A population refers to a group of individuals of the same species that live in the same area and interact with one another. In this case, the mussels of the same type make up a population as they are living together in close proximity on the rocky beach.

The correct answer is "all of the above" because a population can be affected by predation, which means that predators can limit the growth of a population by hunting and killing its members. Lack of nutrients can also limit population growth as it can lead to malnutrition and reduced reproductive success. Similarly, a reduction in light can affect population growth, especially for photosynthetic organisms, as it can limit their ability to produce energy through photosynthesis. Therefore, all three factors (predation, lack of nutrients, reduction in light) can contribute to slowing or stopping the growth of a population.

The term "by-catch" refers to the unintentional catch of non-target species while fishing for more valuable species. These non-target species are often considered as "junk species" because they are not the desired catch and are typically discarded or used for other purposes. This by-catch can include various marine organisms such as fish, turtles, seabirds, and marine mammals, and it is a significant concern as it can lead to overfishing and harm to the ecosystem.

The correct answer is the northwest pacific. The northwest pacific is considered the major fishing area in the world due to its abundant marine resources and diverse fish populations. This region is known for its large-scale commercial fishing operations and is home to some of the most productive fishing grounds, including the Sea of Japan, East China Sea, and the Bering Sea. The northwest pacific supports a significant portion of the global seafood supply and plays a crucial role in meeting the demand for fish products worldwide.

Bacteria thriving around deep sea hydrothermal vents are chemiosynthetic. This means that they obtain their energy by converting inorganic compounds, such as hydrogen sulfide, into organic matter. They do not rely on sunlight for energy like photosynthetic bacteria do. These chemiosynthetic bacteria play a crucial role in the ecosystem by providing a source of energy for other organisms in the deep sea.

Trawls are nets that are dragged along the bottom or through the water column. This method allows the trawls to catch fish and other marine organisms that are swimming or residing in these areas. By being dragged, the trawls can cover a larger area and increase the chances of catching a significant amount of fish. This method is commonly used in commercial fishing to catch a large number of fish in a single haul.

Traditional fisheries are characterized by the use of relatively simple gear and methods. This means that they employ traditional and age-old techniques for catching fish, rather than relying on modern and advanced technologies. These methods may include the use of nets, traps, or simple fishing lines. The emphasis is on simplicity and sustainability, with a focus on maintaining the balance of the ecosystem and preserving traditional fishing practices.

The maximum sustainable yield refers to the highest catch that can be taken from a population without causing overfishing. This means that the catch should be limited to a level that allows the population to replenish itself and maintain its size in the long term. By setting the catch at this maximum sustainable yield, we can ensure that the population remains healthy and can continue to provide a consistent harvest without depleting its numbers.

The bacteria that thrive around deep sea hydrothermal vents obtain their energy from hydrogen sulfide. These vents release hot, mineral-rich fluids that contain high concentrations of hydrogen sulfide. The bacteria have adapted to utilize this hydrogen sulfide as an energy source through a process called chemosynthesis. They convert the hydrogen sulfide into organic compounds, which provide the necessary energy for their survival and growth. This unique ability allows these bacteria to thrive in extreme environments where sunlight is not available, making hydrogen sulfide the primary energy source for these organisms.

Deep sea benthic animals have the major advantage of their food falling to the bottom and staying in one place. This allows them to easily access and consume their food without having to search or compete for it like pelagic animals. The stationary nature of the food source makes it easier for benthic animals to digest and utilize the nutrients efficiently.

China is the correct answer because it is known for having a large and active fishing industry. Despite concerns about overfishing and declining fish stocks worldwide, China has continued to maintain high annual catches since the 80s. This can be attributed to China's vast coastline, large population, and strong demand for seafood. The country has implemented various policies and regulations to manage its fisheries, but the scale of its fishing activities has made it challenging to effectively control and reduce catches. As a result, China's annual catches have remained consistently high over the years.

The correct answer is a kelp forest plus all organisms living in it. A community refers to all the different species of organisms that live and interact in a particular habitat. In this case, a kelp forest is a specific habitat, and the community would include not only the kelp itself but also all the other organisms that live within the forest, such as fish, sea otters, and various types of invertebrates.

The correct answer is "late 1980s". This is the time period when the world population reached 5 billion.

The exclusive economic zone (EEZ) of a nation is equal to 200 nautical miles. This zone extends from the country's coastline and gives the nation exclusive rights to explore and exploit natural resources in the surrounding waters. It also grants the country jurisdiction over activities such as fishing, drilling for oil, and mining within this zone. The 200 nautical mile limit is based on the United Nations Convention on the Law of the Sea (UNCLOS), which was established to regulate maritime boundaries and ensure the sustainable use of ocean resources.

Demersal catches refer to the type of catches that are harvested from the bottom of the water bodies. This means that the correct answer is "the bottom". Demersal species are typically found near or on the seabed, such as flatfish, cod, and halibut. These species are often caught using bottom trawling or bottom longline fishing methods. Therefore, the correct answer accurately describes the location from which demersal catches are harvested.

This answer correctly links the type of organisms with the way they live. Nekton refers to organisms that are capable of swimming and moving independently in the water column, such as fish, turtles, and whales. Therefore, organisms that are part of the Nekton swim.

The ecological niche of a species refers to its specific role or function within the community it inhabits. This includes its interactions with other species, its position in the food web, and its contribution to ecosystem processes. The habitat refers to the physical environment where a species lives, while the mode of reproduction refers to the specific method by which a species reproduces. Therefore, the best definition of ecological niche is the role a species plays in the community.

The correct answer is herrings, sardines, and other clupepoids. This is because tuna and salmon are not clupepoids, but herrings, sardines, and other clupepoids are known to have the largest fish catches.

Coral reefs are primarily found in warm, shallow waters where temperatures range between 23–29°C (73–84°F) and where there is ample sunlight. These conditions are necessary for the photosynthesis of the symbiotic algae (zooxanthellae) that live within coral tissues and provide them with essential nutrients. Oceanic salinity and tidal ranges are also important but not as critical as temperature and light availability.

Competition refers to the type of interaction that occurs when a resource is limited and one organism utilizes the resource at the cost of another organism. In this scenario, the organisms compete for the scarce resource, leading to a struggle for survival and the potential for one organism to outcompete the other. This can result in a decrease in the population of the organism that is unable to access the resource, while the organism that successfully obtains the resource may experience population growth.

The ecosystem best encompasses the community or communities and the physical environment. This is because an ecosystem refers to the interaction between living organisms (community or communities) and their physical surroundings (physical environment). It includes the relationships, energy flow, and nutrient cycling between these components. The concept of an ecosystem emphasizes the interconnectedness and interdependence of both living and non-living elements in a specific area.

Coastal upwelling is the process where cold, nutrient-rich water from the ocean depths rises to the surface. This nutrient-rich water supports the growth of phytoplankton, which in turn attracts small fish and other marine organisms. These small fish then become food for larger fish, creating a thriving ecosystem and attracting commercial fishing activities. Therefore, the major fishing areas of the world are mostly located in waters where coastal upwelling takes place.

The correct answer is the continental shelf. The continental shelf is the shallow, submerged portion of a continent that extends from the shoreline to the drop-off point where the ocean floor begins to slope more steeply. It is a rich and productive area that supports a diverse range of marine life, including fish, shellfish, and other organisms that are commonly harvested for food. The continental shelf provides important habitats and feeding grounds for many species, making it a prime source for marine foods. Coral reefs, open waters, and estuaries also support marine life, but they are not the primary source of marine foods as compared to the continental shelf.

Krill, which are small shrimp-like crustaceans, are primarily found in the cold waters of Antarctica. The Southern Ocean surrounding Antarctica is home to large populations of krill, making it the main location for commercial krill fishing. This region provides the ideal habitat and food sources for krill, and it is where the majority of the world's krill catch comes from. The other options, Alaska, Russia, and Salt Lake City, do not have the same suitable conditions for krill populations and are not major krill fishing locations.

In the year 2000, approximately 10% of the total world consumption was accounted for by farmed fish. This indicates that the production and consumption of fish from aquaculture had significantly increased by that time, making up a significant portion of the global fish supply.

Fishing effort refers to the amount of activity put into fishing, typically measured by factors such as the number of fishing boats and the number of fishermen involved. It does not include the number and size of fishing nets, as this is more related to the fishing gear used rather than the actual effort put into fishing.

Open mariculture refers to the type of mariculture that occurs under natural conditions with minimal human intervention. This means that the cultivation of marine organisms, such as fish or shellfish, takes place in their natural environment without significant manipulation or control by humans. In open mariculture, the organisms are allowed to grow and reproduce naturally, relying on the surrounding ecosystem for their sustenance. This approach is often considered more sustainable and environmentally friendly compared to other forms of mariculture that involve extensive human intervention.

Finfish and shellfish provide approximately 30% of the animal protein consumed by humans around the world. This is a significant percentage, indicating that seafood plays a crucial role in meeting the protein needs of people globally. Seafood is a valuable source of essential nutrients, including omega-3 fatty acids, vitamins, and minerals. It is also a popular food choice due to its variety of flavors and culinary versatility. Therefore, it is not surprising that finfish and shellfish contribute significantly to the overall animal protein intake of the global population.

Clupepoid fish are known to feed on plankton. Plankton is a microscopic organism that serves as a primary food source for many small fish species. Clupepoid fish, being part of this group, rely on plankton as their main source of nutrition. They have specialized feeding mechanisms that allow them to filter and consume these tiny organisms from the water. This feeding behavior is essential for their survival and plays a significant role in the ecological balance of aquatic ecosystems.

Most commercial fisheries around the world have been affected by overfishing. This is due to a combination of factors such as increased demand for seafood, advancements in fishing technology, and inadequate management and regulation of fishing practices. Overfishing occurs when fish are harvested at a rate that exceeds their ability to reproduce and replenish their populations. This leads to a decline in fish stocks and can have severe ecological and economic consequences. While it is difficult to determine the exact percentage of fisheries affected, it is widely recognized that overfishing is a significant issue globally.

The shrimp that occurs in large numbers around deep sea hydrothermal vents does not have eyes, but it has light-sensitive cells on top of its body. These cells are likely used to detect faint light from the vents. Since the hydrothermal vents emit heat and light, it would make sense for the shrimp to use these light-sensitive cells to navigate and locate the vents, which provide a source of warmth and nutrients. Detecting faint light from the vents would be crucial for the shrimp's survival and ability to thrive in its deep-sea habitat.

Predation refers to the act of one organism consuming another organism for food. This can include animals eating other animals, animals eating plants, or even animals consuming microorganisms. The correct answer, "an animal eating any other organism," encompasses all these possibilities and accurately defines predation.

The giant deep sea hydrothermal vent tubeworm does not have a mouth, so it is unable to feed on plankton or detritus. Instead, these tubeworms rely on a symbiotic relationship with chemosynthetic bacteria. The bacteria live inside the tubeworm's body and produce organic molecules using the chemicals found in the hydrothermal vent fluids. The tubeworm absorbs these organic molecules through its body wall, providing it with the necessary nutrients for survival. Therefore, the correct answer is "none of the above, it has no mouth."

 Riftia pachyptila, commonly known as the giant tube worm, is specifically adapted to live in the extreme conditions of hydrothermal vent environments found on the ocean floor. These organisms rely on chemosynthetic bacteria living in their tissues to convert the chemicals from the vent (such as hydrogen sulfide) into energy. The other species listed do not inhabit such extreme environments.

Seeding in mariculture refers to the process of removing diseased fish. This is done to prevent the spread of diseases within the mariculture system. By removing the infected fish, the overall health and well-being of the remaining fish can be maintained. This practice helps to ensure that the mariculture operation remains sustainable and productive.