marine biology essay

marine biology essay

Exploring the Wonders of Marine Biology: An In-Depth Analysis

1. Introduction to Marine Biology

In the study of marine life, biology and marine science converge. Biology is the study of life in all its forms, including bacteria, plants, and animals. Marine science involves the knowledge of the sea itself, including important chemical and physical features such as temperature, pressure, and salinity. These features shape the way marine organisms live. Because the earth is a closed system with interconnected components, the chemistry of the sea is related to the chemistry of lakes and other bodies of water. In the History section, we give information about man’s exploration of the sea and how that exploration has sped up in the past two hundred years. The Tools and Techniques section describes how researchers study marine organisms and their environment, what conclusions they hope to reach, and why they are sometimes unable to test their ideas.

Marine biology is the science that studies the organisms that live in the sea. Research using DNA technology, satellites that map the ocean floor, and high-tech scuba gear have greatly expanded our knowledge of marine life in the last thirty years. New groups of animals have been discovered, and new methods of examining abandoned beaches and tidal pools and of testing hypotheses about the relationships of marine plants and animals and the physical and chemical factors in the sea are constantly being tried. Interest in marine biology has also increased. Students who major in marine biology are especially attracted to outdoor experiences both in the university lab and in field work.

2. Ecosystems and Biodiversity in the Ocean

The marine world can be classified into groups of organisms, also known as ecosystems because they present similar environments. An example classification is rocky shores, packed leaves (“Laminaria”, “Ectocarpus”), benthic-muddy, sandy, rocky – in low-light levels, rocky – in high-light levels, concentrated leaves (“Zostera marina”), “meadows” of gorgonian, and coastal waters. The flow of energy has its origin in the “primary production” produced by the organisms that contain chlorophyll. The energy resulting from the “photosynthesis” of the plant is passed on from organism to organism until it is lost as heat. In the ocean, this primary production is at a maximum because different depths allow for different levels of light energy. However, once the production has been carried out, it is necessary for nutrient supply through moving the water from the bottom. Gradually when depth increases, the surface water temperature also decreases, which creates vertical movements called thermodynamics. These movements favor the rise in nutrients present at the bottom, which, because of the great number of productions of the cyanobacteria present, rise to the surface. The photosynthesis is then performed, and the cycle repeats. After meetings between algae and the plants, small crustaceans which also have the capacity for photosynthesis growth from the bottom.

Leaving aside the awe of knowing that marine biologists exist, it is important to recognize that their premise, when working with the marine world, is to observe, understand, discover, and protect. To be good marine biologists, one needs to know the marine ecosystems and the organisms that interact in them. The marine environment is characterized by a great variety of large environmental factors such as variations in temperature, salinity, oxygen concentration, light intensity, pressure, the solid support (substrate), the food supply, or the breeding areas, the waves’ intensity, and marine currents. Different sorts of life are adapted to different environments in the ocean. When the differences are extreme between two points, only a few organisms are adapted. However, if the differences are relatively beneficial, the organisms have a more general character than the other biotic factors.

3. Adaptations and Behaviors of Marine Species

Many marine animals make use of different color variations in their behavior. Some fish can change color to match their environment by contracting pigment-filled cells called chromatophores; others rely on countershading, whereby their body parts produce a certain color to cancel out the animal’s normal appearance. The biggest impact of color variations occurs in reef species whose color varieties are part of a display used during courtship and spawning. This color flash is an important part of dictating the behaviors of the other sex and signifies readiness for mating. The color change can then signal the release of gametes for fertilization. In many cases, the color flash is also associated in some manner with the variety of environmental cues that add up to a predictable reproductive cycle. These cues include temperature, photoperiod, and possibly lunar phase.

Animal behavior is largely a product of the animal’s physiological adaptations and the conditions existing in the environment. Marine animals face a unique set of environmental conditions: high concentrations of salts, the tendency of water to conduct heat and disperse, and the effects of tides, salinity, temperature, oxygen levels, and light. As a result, marine animals have evolved a number of interesting and unique adaptations to these challenges. Hydrodynamics also play a large role in the marine world, affecting the shape, buoyancy, and vertical displacement of marine organisms. The body plans of swimming animals can be radically different and are influenced by the density of the water around them: motor and sensory aspects are all a function of the physical properties of water.

4. Human Impacts on Marine Environments

The discovery of the Monterey Submarine Canyon’s role in the bay’s incredible fish productivity led to its overharvest by humans. A rapid depletion of sardines ensued and was followed by spongey rubber balls clogging the nets of sardine fishermen, driving fish populations and their prey from the bay. Similarly, once productive Alaskan canneries for herring, cod, and other species were shut down. In the Mediterranean, the anchovy population crashed due to overfishing and recovering the population took decades. Such evidence underlines the notion that changes in the ambitiousness of marine environments can have long-term effects. Yet the extraction and pollution from marine environments persist. Currently 10% of the world’s land and 1.2% of the ocean has the protection of national parks or marine reserves although they are beginning to alleviate some of the human-induced devastation.

Just as human impacts have affected other parts of the world, marine environments have similarly been exploited virtually beyond traditional levels. For example, overharvested fisheries often cause a rapid shift in population characteristics as the larger, older individuals are targeted. Without the older, larger individuals, the fish no longer have their traditional roles in aggregating and dispersing, predator-prey relations, resource partitioning, waste production, and other ecological processes. With such a change in the population composition of a key species, disruptive consequences are likely to occur that can alter the ecosystems in which they live. Unfortunately, these impacts are often unnoticed because of the difficulty in robustly measuring populations of most marine species. One exemplification of this natural catastrophe occurred in Monterey Bay, California, which was once unsurpassed and famous for its sardine and squid abundance and the fishing industry it attracted. In the mid-twentieth century, the bay’s warm, rich waters were indeed vital to the many marine organisms it supported.

5. Future Directions in Marine Biology Research

We suggest a future of marine biology that is more than the sum of our parts, that rises to a greater challenge and creates new and lasting methodologies, applications, and understanding. There are opportunities to forge ahead into relatively uncharted territory, engage in speculative discovery, and offer innovative solutions to challenging problems in marine biomedicine, genomics, and even biodiversity studies. These exclusions only serve to limit the potential value of marine biology research. Inspired by nature not only provide breakthroughs of fundamental significance but also provide the raw materials for, and insights into, new tools and approaches relevant to the full range of biological sciences.

In the future, marine biology will continue to lead the charge in the development of innovative new technologies. These range from underwater robotics to high-tech instruments and characterizing genome activity in the wild. The creation and maintenance of the Ocean Observatories Initiative and the Census of Marine Life Whale Map would have been impossible without the interdisciplinary blend of engineering, robotics, and biology. As our discoveries take us ever deeper into the ocean, we are exposed to an even more astounding variety of new genes, enzymes, and other natural products. We see an urgent need to further study, understand, and take advantage of the biodiversity of marine microorganisms.