Edem Mahu | |
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Born | |
Alma mater | University of Ghana |
Scientific career | |
Institutions | San Jose State University University of Ghana |
Edem Mahu is a Ghanaian marine scientist who is a senior lecturer at the University of Ghana. Her research considers ocean health, oyster fisheries and climate change. She was awarded the 2022 American Geophysical Union Africa Award for Research Excellence in Ocean Sciences.
Mahu applied to study medicine at university, but decided to move into oceanography and fisheries. [1] She earned her doctorate in oceanography at the University of Ghana. [2] Upon receiving the 2022 American Geophysical Union Africa Award for Research Excellence in Ocean Sciences, Mahu reflected on her choice of careers:
I must confess that the decision to pursue a career in ocean sciences in West Africa was intrepid. The most rewarding aspect of this journey has been my ability to serve our global community, mentor several young scientists, and facilitate the development of ocean science capacity in Africa, while at the same time striving to develop my research as a young woman scientist. [3]
Her research made use of radioisotopes in reconstructing the pollution history of heavy metals in the shores of the Gulf of Guinea. She analyzed sediment cores and built a database that described trace metal distribution and toxicity. [4] During her doctoral research, she completed two research placements in the San Jose State University, where she worked at the Moss Landing Marine Laboratories. [1] [4] [5] After earning her doctorate, Mahu became the first marine biogeochemist in Ghana. [5]
Mahu started working on an Organization for Women in Science for the Developing World project to develop cheap android coupled soil nutrient test kits for Ghanaian farmlands. [6] Mahu works on an International Foundation for Science project that looks to understand the toxicity of heavy metal pollution in Ghana.[ citation needed ] She is a member of "Employment of female researchers in Key Assignments" (ERIKA), part of the Partnership for Observation of the Global Oceans (POGO) forum that looks to improve the representation of women in marine research. [7] She is trustee of the Partnership for Observation of the Global Ocean.
Mahu's research seeks to improve ocean health through restoring declining oyster population in Ghana. [1]
A coast – also called the coastline, shoreline, or seashore – is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape, as well as by water induced erosion, such as waves. The geological composition of rock and soil dictates the type of shore that is created. Earth contains roughly 620,000 km (390,000 mi) of coastline.
The seabed is the bottom of the ocean. All floors of the ocean are known as 'seabeds'.
Marine debris, also known as marine litter, is human-created solid material that has deliberately or accidentally been released in seas or the ocean. Floating oceanic debris tends to accumulate at the center of gyres and on coastlines, frequently washing aground, when it is known as beach litter or tidewrack. Deliberate disposal of wastes at sea is called ocean dumping. Naturally occurring debris, such as driftwood and drift seeds, are also present. With the increasing use of plastic, human influence has become an issue as many types of (petrochemical) plastics do not biodegrade quickly, as would natural or organic materials. The largest single type of plastic pollution (~10%) and majority of large plastic in the oceans is discarded and lost nets from the fishing industry. Waterborne plastic poses a serious threat to fish, seabirds, marine reptiles, and marine mammals, as well as to boats and coasts.
Marine pollution occurs when substances used or spread by humans, such as industrial, agricultural and residential waste, particles, noise, excess carbon dioxide or invasive organisms enter the ocean and cause harmful effects there. The majority of this waste (80%) comes from land-based activity, although marine transportation significantly contributes as well. It is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. This pollution results in damage to the environment, to the health of all organisms, and to economic structures worldwide. Since most inputs come from land, either via the rivers, sewage or the atmosphere, it means that continental shelves are more vulnerable to pollution. Air pollution is also a contributing factor by carrying off iron, carbonic acid, nitrogen, silicon, sulfur, pesticides or dust particles into the ocean. The pollution often comes from nonpoint sources such as agricultural runoff, wind-blown debris, and dust. These nonpoint sources are largely due to runoff that enters the ocean through rivers, but wind-blown debris and dust can also play a role, as these pollutants can settle into waterways and oceans. Pathways of pollution include direct discharge, land runoff, ship pollution, bilge pollution, atmospheric pollution and, potentially, deep sea mining.
Plastic pellet pollution is a type of marine debris originating from the plastic particles that are universally used to manufacture large-scale plastics. In the context of plastic pollution, these pre-production plastic pellets are commonly known as 'nurdles'. These microplastics are created separately from the user plastics they are melted down to form, pellets. Loss can occur during both the manufacturing and transport stages. When released into the open environment, they create persistent pollution both in the oceans and on beaches. About 230,000 tonnes of nurdles are thought to be deposited in the oceans each year, where they are often mistaken for food by seabirds, fish and other wildlife. Due to their small size, they are notoriously difficult to clear up from beaches and elsewhere.
A garbage patch is a gyre of marine debris particles caused by the effects of ocean currents and increasing plastic pollution by human populations. These human-caused collections of plastic and other debris are responsible for ecosystem and environmental problems that affect marine life, contaminate oceans with toxic chemicals, and contribute to greenhouse gas emissions. Once waterborne, marine debris becomes mobile. Flotsam can be blown by the wind, or follow the flow of ocean currents, often ending up in the middle of oceanic gyres where currents are weakest.
Marine plastic pollution is a type of marine pollution by plastics, ranging in size from large original material such as bottles and bags, down to microplastics formed from the fragmentation of plastic material. Marine debris is mainly discarded human rubbish which floats on, or is suspended in the ocean. Eighty percent of marine debris is plastic. Microplastics and nanoplastics result from the breakdown or photodegradation of plastic waste in surface waters, rivers or oceans. Recently, scientists have uncovered nanoplastics in heavy snow, more specifically about 3,000 tons that cover Switzerland yearly.
The North Atlantic garbage patch is a garbage patch of man-made marine debris found floating within the North Atlantic Gyre, originally documented in 1972. A 22-year research study conducted by the Sea Education Association estimates the patch to be hundreds of kilometers across, with a density of more than 200,000 pieces of debris per square kilometer. The garbage originates from human-created waste traveling from rivers into the ocean and mainly consists of microplastics. The garbage patch is a large risk to wildlife through plastic consumption and entanglement.
Microplastics are fragments of any type of plastic less than 5 mm (0.20 in) in length, according to the U.S. National Oceanic and Atmospheric Administration (NOAA) and the European Chemicals Agency. They cause pollution by entering natural ecosystems from a variety of sources, including cosmetics, clothing, food packaging, and industrial processes. The term microplastics is used to differentiate from larger, non-microscopic plastic waste. Two classifications of microplastics are currently recognized. Primary microplastics include any plastic fragments or particles that are already 5.0 mm in size or less before entering the environment. These include microfibers from clothing, microbeads, plastic glitter and plastic pellets. Secondary microplastics arise from the degradation (breakdown) of larger plastic products through natural weathering processes after entering the environment. Such sources of secondary microplastics include water and soda bottles, fishing nets, plastic bags, microwave containers, tea bags and tire wear. Both types are recognized to persist in the environment at high levels, particularly in aquatic and marine ecosystems, where they cause water pollution. 35% of all ocean microplastics come from textiles/clothing, primarily due to the erosion of polyester, acrylic, or nylon-based clothing, often during the washing process. However, microplastics also accumulate in the air and terrestrial ecosystems. Because plastics degrade slowly, microplastics have a high probability of ingestion, incorporation into, and accumulation in the bodies and tissues of many organisms. The toxic chemicals that come from both the ocean and runoff can also biomagnify up the food chain. In terrestrial ecosystems, microplastics have been demonstrated to reduce the viability of soil ecosystems. As of 2023, the cycle and movement of microplastics in the environment was not fully known. Deep layer ocean sediment surveys in China (2020) show the presence of plastics in deposition layers far older than the invention of plastics, leading to suspected underestimation of microplastics in surface sample ocean surveys.
Hava Wienograd Len Hornung was Israel's first female oceanographer and instrumental in the establishment of the first oceanographic research station in Israel, the Sea Fisheries Research Station, or "Tahanah le-heker ha-dayig hayami". She was one of the catalysts for oceanographic research in Israel, which eventually culminated in larger Israel Oceanographic and Limnological Research Center (IOLR) in 1967, which continues to do cutting-edge research to this day.
Mercury is a heavy metal that cycles through the atmosphere, water, and soil in various forms to different parts of the world. Due to this natural mercury cycle, irrespective of which part of the world releases mercury it could affect an entirely different part of the world making mercury pollution a global concern. Mercury pollution is now identified as a global problem and awareness has been raised on an international action plan to minimize anthropogenic mercury emissions and clean up mercury pollution. The 2002 Global Mercury Assessment concluded that "International actions to address the global mercury problem should not be delayed". Among many environments that are under the impact of mercury pollution, the ocean is one which cannot be neglected as it has the ability to act as a "storage closet" for mercury. According to a recent model study the total anthropogenic mercury released into the ocean is estimated to be around 80,000 to 45,000 metric tons and two-thirds of this amount is estimated to be found in waters shallower than 1000m level where much consumable fish live. Mercury can bioaccumulate in marine food chains in the form of highly toxic methylmercury which can cause health risks to human seafood consumers. According to statistics, about 66% of global fish consumption comes from the ocean. Therefore, it is important to monitor and regulate oceanic mercury levels to prevent more and more mercury from reaching the human population through seafood consumption.
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Parthasarathi Chakraborty is an Indian environmental geochemist, a former senior scientist at the CSIR-National Institute of Oceanography and an associate professor at the Indian Institute of Technology Kharagpur, India. Chakraborty is known for his studies in the field of Environmental Chemistry. He made contributions to the field of Environmental Geochemistry which has facilitated our understanding of the metals-natural ligands interactions in natural and marine environments. He is a recipient of the National Geoscience Award-2015 and an elected fellow of the Indian Geophysical Union.The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, for his contributions to Earth, Atmosphere, Ocean and Planetary Sciences in 2018.
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