Climate change will affect the distribution and diversity of marine organisms

Climate change will force marine organisms towards the poles, but would they be safe there? 

Human activities such as emissions from the use of fossil fuels, rampant urbanisation, deforestation, and modern agricultural practices, are all altering the earth’s climate in an unprecedented scale. Climate change not only occurs in the land, but also in water bodies. Studies have indicated that since the 1950s, the amount of heat stored in the ocean (ocean heat) has increased considerably. Besides, ocean temperatures have increased throughout the world since the advent of the twentieth century, with the past three decades recording the highest temperatures since the measurements began.

 A major consequence of increase in ocean temperatures is the corresponding decrease in dissolved oxygen levels. This phenomenon is predicted to significantly disturb marine ecosystems. Recent research by a group of American and German scientists revealed the consequences of oceanic climate change on a range of fish and crustacean species in the North Atlantic with different levels of tolerance towards heat and oxygen levels. The researchers'  climate models predict substantial warming and deoxygenation throughout most of the upper ocean by the end of this century which in turn will affect the distribution  of marine  creatures. Their studies reveal that warming of water and oxygen depletion would force the organisms to migrate towards the pole due to deficiency of the original native waters to sustain their energy requirements. The scientists predict that even the waters towards the pole would have reduced oxygen levels, meaning the survival of the migrants could be precarious even there. Furthermore, this movement could alter the ecosystems in the polar waters due to many factors including competition from the migrants which may alter species ecologies.

References

http://www.sciencemag.org/content/348/6239/1132.abstract

Deutsch C, Ferrel A, Seibel B, Pörtner HO, & Huey RB (2015). Ecophysiology. Climate change tightens a metabolic constraint on marine habitats. Science (New York, N.Y.), 348 (6239), 1132-5 PMID: 26045435

Pesticides Kill Wildlife in India

Media reports from India indicate that the carcasses of 5 tigers found dead  between  2012 to 2015 in the Indian state of Uttar Pradesh between the period  were found to contain organochlorine pesticides notably DDT. It is thought that the tigers consumed  pesticide laced carcasses  of dead animals  which were used as  baits which resulted in their death. Some of the tiger carcasses were found to lack nails, forelimbs and whiskers. Tiger parts are used for local occult practices and also have a lucrative market in Tibet and China.

Precious wildlife like this are killed either intentionally or unintentionally by pesticides. Pesticides are used  by  poachers who illegally trade animal parts. Pesticides are also used by  irate farmers who lose their livestock due to the wild carnivores for  taking ‘revenge’  . Sometimes, wildlife stray into fields and crop estates and unknowingly consume crops laced with pesticides resulting in debilitation and death.

5 years ago, two tiger cubs were killed in Ranthmabore NationalPark by villagers who allegedly killed the tigers by baiting them with goat laced with the deadly pesticide Aldrin in ‘revenge’ of the tigers killing their cattle.

Often wildlife is killed accidentally such as when they consume crops laden with pesticides. In 2011, deaths of two pregnant elephants and other animals in tea estates around Kazinranga  national park in  Assam  was reported . The park is home to the Indian one horned rhinoceros  and about 50 per cent of the endangered  Asiatic wild water buffalo.  The elephants had been killed by eating insecticide laced grass in the tea gardens outside the confines of the national park. This highlighted serious problems in the area . Tea estates are sprayed with pesticides, which drifts into the nearby areas onto the grass and waterways. Wild herbivores and domestic livestock that feed on the grass contaminated with pesticides often die. The deaths however do not end there though. Scavengers including vultures that feed  on the carcasses of the animals are then exposed to the pesticides  which in turn results in more deaths.

Earlier in April of this year, an elephant was found  outside the forest area in Mankarai, Tamilnadu suffering from severe ulcers in and around its mouth, which prevented it from feeding . Wildlife conservationists  attributed this to the consumption of corps laden with pesticides by the hapless animal.