El Nino: Its Importance to You
Good morning/afternoon/evening, SUFB Crew! Andrew and I wanted to take some time today to talk about the weather with you. While it unfairly has a stigma of being the topic of boring small talk with people you don’t really like, the weather is actually extremely important to marine ecosystems. We want to share one, relevant example of how changes in the weather can impact fish migrations, plankton populations, and the fishery industry.
An El Niño event is currently forming in the middle of the Pacific Ocean, and this phenomenon will likely impact the ocean’s production for the next couple of years. First, let’s just make sure we’re all working from the same playbook. An El Niño is essentially a warming of ocean waters driven by cyclical weather patterns in the Pacific Ocean. According to NOAA, this warming is defined as a three-month period with an average warming of 0.5° C or greater. These conditions happen typically every two to seven years, and can last for a few months to a couple years.
Now, like any prolonged change in sea surface temperatures, El Niño events can cause shifts in the distribution of certain marine species. Fish, mammals, and mobile invertebrates that are used to the cooler waters of the Pacific will migrate north during El Niño events, while tropical or warm water species will expand their range to exploit the greater area of suitable temperatures. Normally these shifts wouldn’t necessarily be cause for worry; since El Niño is cyclical, this sea surface warming doesn’t represent a permanent change. However, this year El Niño’s effects will be compounded by another presence in the Pacific.
Meet the Blob. The Blob is a large area of unusually warm water in the East Pacific stretching from Mexico to Alaska. It was first detected in 2013, though its origin is still being debated. Researchers can’t seem to agree if it’s a cyclical phenomenon, a result of climate change, or some combination of both. What is pretty well established, though, is that the combination of the cyclical warming caused by El Niño and the abnormally higher current sea surface temperatures could cause issues for any marine organisms in the Pacific that require food.
(Here is the Saturday Night Live Rendition of El Nino…a little humour for your Monday!)
Cooler waters typically contain more snacks and such for fish, invertebrates, and mammals than warmer waters. This is because of a phenomenon seen in lower temperature waters called upwelling, where wind currents drive the mixing of nutrient-rich deeper waters with the surface waters. This means all of the plankton, specifically copepods (one of the most abundant animals on earth), get a free ride to the top of the ocean where all of their predators live. So, cooler waters means more upwelling, which means more food for a lot of economically important marine animals. With both of these warming events occurring at the same time, not only will mobile species need to migrate north and away from their current feeding grounds, but a large portion of the Pacific ocean will have less food available than normal. This could cause significant declines in fish and marine mammal populations that rely on spatially and temporally consistent prey availability. You might also have guessed that shifting species distributions will adversely affect many Pacific fisheries, causing a notable drop in that industry as well. Therefore, it’s vital that we become informed consumers of seafood over the next year. These Pacific ecosystems are already under pressure from industrial fishing, man-made climate change, and pollution. The Blob and the Godzilla El Niño certainly aren’t helping.
Enjoy the Podcast!