**11. Declining marine life**

Having looked at the changes in global forests, we look at the present widespread decline in marine life, fisheries, coral ecosystems, etc. It is widely acknowledged that marine life has been decreasing at an alarming rate over the last few decades (Reynolds, 2005; Marinebio.com, 2011).

The most common explanation for the decline of marine life is global warming (SFGate.com, Dec. 2011). Global warming as the cause of declining marine life raises questions which cannot be easily answered. It implies that fish which used to live at the equator would shift to higher latitudes (Figure 10). Fish formerly of higher latitudes would now shift to the arctic circle. Instead, marine life, including plankton, is found to have decreased dramatically worldwide, strongly indicating a cause other than global warming.

The issue arises as to why trees and vegetation have benefited, at least marginally, whereas marine life has declined alarmingly over the decades.

Modern Transitions in Saving Energy and the Environment 211

the fishes are very sensitive to contamination in the water. Those in charge of aquariums, especially marine aquariums, are aware that fishes may be harmed or killed by even quantities of toxins. As any hobbyist with a fish tank may know, dropping a small contaminant such as a cigarette butt, could easily kill a tankful of fish. The exception to this could be fish which have coexisted with humans for a long time, (such as gold fish) and

Large numbers of fishes are known to wash up on shores, often for no apparent reason; a phenomena for which contamination is a likely explanation. A satisfactory explanation has not been found for why whales and other fish beaching, and ultimately killing themselves. This act of self-destruction is clearly highly destructive to the continuity of their genes, from an evolutionary point of view. One possible explanation for this counter-evolutionary behaviour of fishes beaching themselves could be to get away from chemically contaminated waters. The chemicals in the water may also confuse the fish into getting

A major concern associated with global warming, the melting of polar ice, and rising ocean levels, is flooding of low lying areas of the world. It is feared that within decades, ocean levels may rise over inches or feet, inundating low lying areas, especially river deltas such as

Fig. 11. Rising sea levels causing a shift in the equilibrium of the land river and sea in a river

It has been seen that river deltas (such as the Ganges delta of Bangladesh) are dynamic systems, where the land levels are the equilibrium point of the opposing forces of silt deposition and erosion (S. Khan, 1991) . This equilibrium concept of land level is also applicable to other deltas, such as for the Mississippi (in Louisiana), the Nile (in Egypt). It has been seen that for the last few decades, coastal land is being added at the rate of several feet every year. Considering that global warming rates have been mostly constant over decades, and is expected to be constant for the next few decades, it is likely that the trend of coastal land addition will continue at its present rates. It is unlikely that the coastal land addition will reverse over the next few decades causing coastal land loss or inundation. A

Sea

Rising sea level

those that have learnt to survive well in contaminated waters (farmed fish).

away from the water into the beach.

River with silt from upstream

Land

Rising land level

In response to rising sea

delta. The land level rises as sea levels rise.

**12. Rising ocean levels** 

Bangladesh.
