By: Melissa Santiago
Human Impact to Marine Life and Global Warming
Some of the main threat to marine life are ocean acidification, climate change, and global warming. But humans pose a great on our marine life as well, whether it is overfishing or by the garbage which we dispose of in our seas.
According to the National Oceanic Atmospheric Administration (2018), “each year, billions of pounds of trash and other pollutants enter the ocean”. Marine debris injures and kills marine life, interferes with navigation safety, and poses a threat to human health. Our oceans and waterways are polluted with a wide variety of marine debris, ranging from tiny microplastics to derelict fishing gear and abandoned vessels. The article speaks about how too much nutrients can cause alga bloom which is an overgrowth of algae. This is caused by nutrients such as nitrogen and phosphorus which are needed for plant growth.
Humans have engaged in activities that produce black carbon particles. Black carbon particles are released into the atmosphere in the form of smoke that is produced by cooking with solid animal fuels, burning trees, and spewing diesel exhaust. When black carbon particles reach the atmosphere, they form a heat-absorbing layer that causes temperatures to rise. Raindrops tend to form around black carbon particles in the atmosphere, and when they fall to the ground, they absorb heat there too, thus magnifying their warming effect.
Fertilizers used in farming have had far-reaching effects. Their use has injected vast amounts of nitrogen and phosphorous into regional ecosystems.120 million tons of nitrogen are removed from the atmosphere each year and 20 million tons of phosphorous is mined from the ground in order to produce fertilizer to be used for farming. These practices add a tremendous amount of nitrogen and phosphorus to the biosphere than would occur naturally. Runoff from farmland often carries large amounts of fertilizer into rivers and streams that eventually drain into the sea. All of this fertilizer runoff creates rapidly expanding marine dead zones
Technological development has led to the invention of new materials, such as plastics, that were previously unknown to the planet. Many of these new materials are made up of chemical compounds that can remain active in the environment for thousands of years and have lasting impacts on the delicate regulatory cycles and ecosystems. At high concentrations, these chemicals can disrupt animal endocrine systems, alter reproduction patterns, and cause cancer. Organic pollutants and plastic-derived endocrine disruptors have been discovered in low concentrations all over the world, even in areas where they’ve never been used, such as Antarctica and at the bottom of the oceans.
According to Current Biology Magazine’s ‘Not so many fish in the sea’(2017), “The Food and Agricultural Organization (FAO), which is under the purview of the United Nations, estimates that in 1950 the amount of fish landed worldwide amounted to 19.3 million tons. That figure had increased to 93.4 million tons in 2014, meaning we are pulling about five times as much fish out of our rivers, lakes, and oceans”.
The long-lived, late reproducing, and low fecundity life histories of many deep-sea organisms increase vulnerability to multiple human pressures and global climate change. Low rates of replacement result in extreme sensitivity to fishing pressure, and weak currents and the absence of wave action result in sometimes fragile organisms that are easily damaged by bottom-contact fishing gear, which now penetrates to thousands of meters depth. Richard (2010) noted, “Deepwater Horizon oil spill, also called Gulf of Mexico oil spill, the largest marine oil spill in history, caused by an April 20, 2010”. The Deepwater Horizon blowout in the Gulf of Mexico clearly demonstrated not only the increasing range of environments in which extraction occurs but also the ecological aftermath cations of major blowouts for deep-sea fauna. Deepsea mining, while still in its infancy, necessarily destroys habitat, whether it concerns extracting polymetallic sulfides at hydrothermal vent chimneys, cobalt-rich crusts from seamounts, or manganese nodules from abyssal sediments. But the global footprint of climate change represents the single greatest concern regarding human impacts on ocean environments, largely through indirect effects.
Most deep-sea environments depend largely on surface production, climate change effects on surface processes will alter deep-sea ecosystems globally with evidence of change already happening. Such changes can significantly affect the growth rates, survival, and recruitment of deep-sea organisms with severe consequences for the potential recovery of deep-sea assemblages compounded by other effects of human activities listed above. These consequences can compromise the success of restoration actions in deep-sea ecosystems affected by different anthropogenic pressures. At the same time, the projected increase in temperature and decrease in oxygen and pH in the deep ocean under present climate change scenarios could have additional detrimental impacts on the metabolism of deep-sea organisms, which appear more sensitive than shallow-water counterparts to any change in environmental conditions. The response of deep-sea life to global changes will depend on the ability of these organisms to adapt to altered conditions and to maintain their biological interactions with other living components. This is the reason we should make a special effort to expand the knowledge of their biology, from their physiology and symbiotic interactions to the factors controlling food webs and the dispersal of deep-sea organisms. The additive effects of human pressures and global climate change are still almost completely unknown and can be addressed only by increasing knowledge on basic and system biology of deep-sea ecosystems and through a better understanding of the complex biological interactions that enable their efficient functioning.