Effects of climate change on marine mammals
Encyclopedia
Climate change
is a cause of increasing concern to scientists and it will have dramatic effects on marine mammals. The increase of carbon dioxide
and other greenhouse gases into the atmosphere are thought to be the main cause of climate change or global warming. Exactly how climate change will affect the ocean, which is home to marine mammals, is hard to predict since there are so many factors that affect ocean ecosystems. How all these, such as weather events and salinity, will interact is highly unpredictable. Using global climate model
s or GCMs scientists can get a general idea of how climate change will impact the ocean environment in the future.
Marine mammals have evolved to live in the ocean, but the effects of climate change may be altering their habitat more rapidly than they can adapt to the changes.
As levels of greenhouse gases in the atmosphere increase, they trap heat which causes an overall warming of the planet. During the last century, global average land and sea surface temperature
has increased dramatically. Many marine mammal
species
require specific temperature ranges in which they must live. The warming of the ocean will cause changes in species range. Those species that cannot relocate due to some barrier will be forced to adapt to the increasingly warming sea waters or else risk going extinct. Many species ranges are being pushed further and further north as water temperatures increase and will soon have nowhere else to go.
Not surprisingly, glacier ice melt has increased while sea ice extent and thickness has decreased as temperatures keep rising. Rises in sea level affect coastal habitat and the species that rely on it. This habitat is often used as haul out sites for several pinniped species. In order to combat rising sea levels in areas inhabited by humans the construction of sea walls has been proposed, however, these walls may interfere with the migration routes of several marine mammal species. These routes can be very important for reaching feeding and breeding grounds.
Changes in temperature ranges will also change the location of areas with high primary productivity. These areas are important to marine mammals because primary producers are the food source of marine mammal prey or are the marine mammal prey themselves. Marine mammal distribution and abundance will be determined by the distribution and abundance of its prey. Migration of marine mammals may also be affected by the changes in primary productivity.
Increased glacier
ice melt also impacts ocean circulation due to the increase of freshwater in the ocean. Salinity concentrations in the ocean are changing. Thermohaline circulation
may be altered by increasing amounts of freshwater in the ocean. Thermohaline circulation is responsible for bringing up cold, nutrient rich water from the depths of the ocean, a process known as upwelling
. This may effect regional temperatures and primary productivity.
Susceptibility to disease is also thought to increase while reproductive success may decrease with increasing ocean temperatures.
The worlds oceans absorb a large amount of carbon dioxide from the atmosphere and causes an increase in carbon dioxide concentrations and a decrease its overall pH
, making it more acidic.
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
is a cause of increasing concern to scientists and it will have dramatic effects on marine mammals. The increase of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
and other greenhouse gases into the atmosphere are thought to be the main cause of climate change or global warming. Exactly how climate change will affect the ocean, which is home to marine mammals, is hard to predict since there are so many factors that affect ocean ecosystems. How all these, such as weather events and salinity, will interact is highly unpredictable. Using global climate model
Global climate model
A General Circulation Model is a mathematical model of the general circulation of a planetary atmosphere or ocean and based on the Navier–Stokes equations on a rotating sphere with thermodynamic terms for various energy sources . These equations are the basis for complex computer programs commonly...
s or GCMs scientists can get a general idea of how climate change will impact the ocean environment in the future.
Marine mammals have evolved to live in the ocean, but the effects of climate change may be altering their habitat more rapidly than they can adapt to the changes.
As levels of greenhouse gases in the atmosphere increase, they trap heat which causes an overall warming of the planet. During the last century, global average land and sea surface temperature
Sea surface temperature
Sea surface temperature is the water temperature close to the oceans surface. The exact meaning of surface varies according to the measurement method used, but it is between and below the sea surface. Air masses in the Earth's atmosphere are highly modified by sea surface temperatures within a...
has increased dramatically. Many marine mammal
Marine mammal
Marine mammals, which include seals, whales, dolphins, and walruses, form a diverse group of 128 species that rely on the ocean for their existence. They do not represent a distinct biological grouping, but rather are unified by their reliance on the marine environment for feeding. The level of...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
require specific temperature ranges in which they must live. The warming of the ocean will cause changes in species range. Those species that cannot relocate due to some barrier will be forced to adapt to the increasingly warming sea waters or else risk going extinct. Many species ranges are being pushed further and further north as water temperatures increase and will soon have nowhere else to go.
Not surprisingly, glacier ice melt has increased while sea ice extent and thickness has decreased as temperatures keep rising. Rises in sea level affect coastal habitat and the species that rely on it. This habitat is often used as haul out sites for several pinniped species. In order to combat rising sea levels in areas inhabited by humans the construction of sea walls has been proposed, however, these walls may interfere with the migration routes of several marine mammal species. These routes can be very important for reaching feeding and breeding grounds.
Changes in temperature ranges will also change the location of areas with high primary productivity. These areas are important to marine mammals because primary producers are the food source of marine mammal prey or are the marine mammal prey themselves. Marine mammal distribution and abundance will be determined by the distribution and abundance of its prey. Migration of marine mammals may also be affected by the changes in primary productivity.
Increased glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
ice melt also impacts ocean circulation due to the increase of freshwater in the ocean. Salinity concentrations in the ocean are changing. Thermohaline circulation
Thermohaline circulation
The term thermohaline circulation refers to a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes....
may be altered by increasing amounts of freshwater in the ocean. Thermohaline circulation is responsible for bringing up cold, nutrient rich water from the depths of the ocean, a process known as upwelling
Upwelling
Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water. The increased availability in upwelling regions results in high levels of primary...
. This may effect regional temperatures and primary productivity.
Susceptibility to disease is also thought to increase while reproductive success may decrease with increasing ocean temperatures.
The worlds oceans absorb a large amount of carbon dioxide from the atmosphere and causes an increase in carbon dioxide concentrations and a decrease its overall pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
, making it more acidic.