Climate change drastically impacts the pattern of marine biodiversity through survival

challenges in species distribution. The bell curve global pattern or marine species richness is

flattening and changing rapidly. This is serious. The tropical water at the equator has the richest

diversity of marine life on Earth. For centuries, the number of species has remained lower at the

poles and peaking at the equator, resulting in a bell-shaped gradient of richness. The number of

marine species tapers off naturally as you head towards the poles. The distance moved by

species are greatest in areas showing the highest levels of warming.


The bell-shaped curve has remained stable until now. The waters at the equator have more

species diversity than the poles due to abundant food sources and warm waters. As ocean

temperatures warm, many marine species will shift due to dependence on specific water

temperature and nutrient availability.  As temperatures shift, so do the marine species seeking

sustainable life. Warmer water temperatures deplete vital nutrients, causing species to migrate

elsewhere for food. When these species shift, so do their predators. When patterns are

disrupted due to a changing climate, it also changes predator/prey relationships and increases

stranding, starvation and poor reproduction in marine species.



Other human stressors in the marine environment include water pollution, overfishing and the

destruction of coastal habitats. As the waters become warmer and less hospitable, many

species migrate to their preferred temperatures for better and sustainable conditions toward

the poles.They are migrating from the equator to the tropics. The equator's rising temperatures

is detrimental because tropical marine species must move constantly to remain in their

reproductive habitat. Many species residing in the equator’s warm waters are migrating to

cooler waters because the water at the equator has become too warm for some species.  As a

result of global warming, more than 80% of Earth’s marine life is migrating to different places

and changing their breeding and feeding patterns. 80%! This migration is happening ten times

faster than the migration of land animals . This results in the flattening of the bell curve from

the equator to the poles. This pole shifting has been documented.



As ocean temperatures warm, many marine species will shift due to dependence on specific

water temperature and nutrient availability, including those species who love cold waters near

the poles and warm water-loving species near the equator. As temperatures shift, so do the

marine species seeking sustainable life. Warmer water temperatures delete vital nutrients,

causing species to migrate elsewhere for food. Once these species shift, so do the predators

that rely on them for food. When the patterns are disrupted due to a changing climate, this 

changes all predator/prey relationships and increases stranding, starvation and poor

reproduction. Other human stressors on our marine environment include water pollution,

overfishing and the destruction of coastal habitats.



Scientists are warning there could be mass extinctions in the near future as species move into

the subtropics, where they will struggle to compete and adapt. All of this could result in a

collapse in the marine ecosystem. In subtropic regions where marine species richness is

migrating, there will be species invaders, new predator-prey interaction and new competitive

relationships. This results in ecosystem collapse when food supplies and other systems are

permanently altered.



These changes have profound implications for human livelihoods.  Many tropical island nations

depend on revenue from fishing fleets purchasing licenses in territorial waters. Highly mobile

marine species, like tuna, are likely to move rapidly toward the subtropics, away from the island

nations that are dependent on them.



What can we do?

1. Aggressively reduce our emissions, as laid out in the Paris Climate Accord.

2. 41 nations are pushing to set a new target of protecting 30% of the ocean by 2030.

3. This 30 by 30 target could ban seafloor mining and remove fishing in reserves that destroy

habitats and release as much CO2 as global aviation. These measures would remove pressure

​on biodiversity and promote ecological resilience.

4. Design climate-smart reserves, where climate would be stable for the foreseeable future.

Our Ocean Food Web Will Be
Severely Disrupted By Warming Oceans

   Specific Species Migration

CLIMATE SCIENCE