#BIO376 Marine Ecology
These are the top blog posts from the Marine Ecology class, BIO376. Congratulations to the authors!
“Lights, Ocean, Action!”: The Effects of Light Pollution on Sea Turtles’ Nesting and
A wise sea turtle once said, “Oh, it's awesome, Jellyman. The little dudes are just eggs, we leave 'em on a beach to hatch, and then, coo-coo-cachoo, they find their way back to the big ol' blue” (Fig. 1) (Stanton 2003). This quote, from Finding Nemo’s Crush, perfectly describes the general process of sea turtle nesting and hatching behaviours in coastal environments (Stanton 2003). To reiterate, female sea turtles lay their eggs on a beach and their hatched offspring will make the treacherous journey back to the water (Hirth 1980, Lutz et al. 2013). It seems quite simple, right? Yet, with the introduction of a new anthropogenic factor, the nesting and hatching behaviours of sea turtles no longer seem to be the same (Longcore and Rich 2004, Oliver de la Esperanza et al. 2017).
‘Whale,’ belugas are endangered: An insight on the population decline of beluga whales (Delphinapterus leucas) in the St. Lawrence Estuary
The current circumstance facing beluga whales shares several similarities with the 1993 film, Free Willy. The film tells the story of a boy named Jesse who is trying to save an orca, Willy, who is on the verge of being killed by aquarium owners. Like Willy the orca, beluga whales are the center of danger due to the impact of human activities. Beluga whales may not be directly hunted by aquarium owners, but they face danger and risk to their populations due to human-caused environmental stressors, such as water pollution. SPOILER ALERT: the film has a happy ending, where Jesse saves Willy from the aquarium and Willy can finally swim freely in the ocean. Unfortunately, can we say the same thing about our beluga whales? Can we be like Jesse and protect beluga whales from population decline?
Sawfishes: Can We Save One of the World’s Most Endangered Group of Marine Fishes from Extinction?
In today’s rapidly changing world, hearing about a species on the precipice of extinction is no longer news. Anthropogenic impacts, from climate change to habitat destruction, has put species across the globe on a rapid trajectory towards mass extinction (Ceballos et al., 2015). Of particular susceptibility is sharks and rays, a group whose often slow-growing populations are subjected to explosive fishing pressures and overexploitation that have only increased over the past few decades (Pacoureau et al., 2021). About three quarters of species within the sharks and rays are facing extinction, with a 71% decline in abundance since 1970 (Pacoureau et al., 2021).
Sawfishes (not to be confused with the sawshark) are rays and are considered to be one of the world’s most threatened group of oceanic fishes (Dulvy et al., 2016; Poulakis & Grubbs, 2019). The sawfish family consists of 5 distinct species: the largetooth sawfish (Pristis pristis), the smalltooth sawfish (Pristis pectinata), the green sawfish (Pristis zijsron), the dwarf sawfish (Pristis clavata) and the narrow sawfish (Anoxypristis cuspidata) (Yan et al., 2021). The first three of these species are considered critically endangered by the International Union for Conservation of Nature (IUCN), while the latter two are listed as endangered (Yan et al., 2021).