Whale Shark Distribution and Environmental Factors
An introduction into the lives of Whale Sharks
According to the IUCN Red List, Whale Sharks are classified as an endangered species. The Green Status Assessment states that much of the population is largely depleted.
Whale Sharks can be found in three of Earth's oceans including the Atlantic, Pacific, and Indian Oceans. The map below shows the range of Whale Sharks:
Map from the IUCN Red List
They typically prefer warm water near tropical climates, which puts the range around the equator.
Photo from Wildest Animal/Getty Images
Whale Sharks are filter feeders and primarily eat plankton, krill, fish eggs, and small fish.
They graze on the surface of the ocean and can dive down to almost 2,000 meters.
Photo from Gregory Sweeney/Getty Images
According to the IUCN Red List, some of the major threats whale sharks face include oil drilling, shipping lanes, biological resource use, and human disturbances.
Due to technical difficulties, my data was obtained from Professor Morales-Ramirez.
The Species Distribution Model from MaxEnt was created from occurrence data and environmental factors which are then run through the MaxEnt program to give the viewer a map of the best predicted areas for whale sharks to live.
Some of the environmental information taken into consideration include water temperature and chlorophyll.
The first graph below shows the likelihood of a randomly chosen point to be represented on the graph with a higher probability of occurrence. The second graph is the receiver operating characteristic and uses the same data as the first. Both factors are above 0.9 which show that the model indicted high performance.
From MaxEnt
From MaxEnt
This Map shows the areas of the world that have better conditions for whale sharks. The red and orange would be the best suited areas for the species where the green and blue would be the worst areas for whale sharks.
From MaxEnt
The following two graphs are the jackknife graphs for variable importance. These show the environmental factors effecting whale sharks such as chlorophyll, water pH levels, and water salinity.
From MaxEnt
From MaxEnt
In conclusion, whale sharks have the best living conditions would be around the Philippines and the highest contributing environmental factors impacting whale sharks include chlorophyll and water salinity.
Information obtained for this project are from the following websites:
- IUCN Red List: https://www.iucnredlist.org/species/19488/2365291
- Ocean Conservancy: https://oceanconservancy.org/blog/2018/08/30/5-fin-credible-facts-whale-sharks/?ea.tracking.id=23HPXGJAXX&utm_medium=PaidSearch&utm_source=GoogleGrants&utm_campaign=FY23&gad_source=1&gclid=CjwKCAiA98WrBhAYEiwA2WvhOg_5F9yhT7zH4lnvyp1kjHFadvzRO0ySfKEyPsZs4gnSjLSzmzRZIhoClZEQAvD_BwE
- NOAA Fisheries: https://www.fisheries.noaa.gov/feature-story/new-publication-highlights-whale-shark-movements-gulf-mexico
