A deep dive into the current state of marine wildlife - Daily Forty-Niner - Daily 49er

Annually on April 22, Earth Day recognizes environmental and climate-changing events that have affected the ecological system, while also advocating to help the planet by introducing alternatives to preserve oceanic and land-based wildlife.

"Restore our Earth" was announced as Earth Day's 2021 campaign theme and emphasizes that "together we can prevent the coming disasters of climate change and environmental destruction," according to the event's official website.

For the second time, Earth Day will be celebrated through a livestreamed event due to the coronavirus pandemic and focus on topics such as climate and environmental literacy, reforestation efforts and cleanups.

Encompassing 71% of the Earth's surface and sustaining the lives of billions of people, the ocean is home to many ecosystems and forms of wildlife. It also "regulates our climate and produces half the oxygen we breathe," according to World Wildlife.

Chris Lowe, Shark Lab director and professor of marine biology at Long Beach State, explained how "the upper 200 meters of the ocean is where light penetrates, so any photosynthetic organisms can be limited" because of oceanic plankton.

"Phytoplankton can grow so fast that they cause red tides that can lead the water to become murky that you couldn't see your hand in front of your face," Lowe said. "When we have bad red tides, they can suck out all the oxygen, and then all the fish would die because they need oxygen to survive."

According to the National Oceanic and Atmospheric Administration, scientists have estimated that about 50% to 80% of oxygen production comes from the Earth, and "oceanic plankton species such as drifting plants, algae and even some bacteria are able to photosynthesize."

Lowe explained that the ocean's temperature is vital for marine wildlife and organisms, comparing how algae invertebrates and fishes would be affected differently due to the lack of oxygen and increasingly heated oceanic temperature.

"Algae invertebrates, such as a barnacle that sits on a rock, wouldn't be able to go anywhere, so if the ocean is getting warmer or there is no oxygen, those animals are going to die," Lowe said. "Fishes would be able to move somewhere else, but some of them might not be able to move fast enough so they might also suffocate and die."

As the endangerment of marine life has increased over the years, the populations of different oceanic species such as sharks have decreased by 71% since 1970, according to USA Today.

Of 31 shark species analyzed during a research study, 24 are threatened with extinction, and the species of oceanic whitetip, scalloped hammerhead and great hammerhead "have declined so sharply that they are classified as critically endangered."

According to Lowe, shark species have become endangered because many of them have been caught as bycatch onto the longlines that many fisheries use to catch tuna while out on the ocean.

"Now, the reason why those sharks don't do well is because of their physiology because if they can't swim, they'll suffocate and die," Lowe said.

According to Oceana, longlines are known to catch sharks "instead of the intended target at least 20% of the time" and are "made up of a mainline that can extend for miles."

On the other hand, blue and tiger sharks have low hooking mortality because "more than 70% of blue sharks and up to 95% of tiger sharks survive after being hooked on a longline" and released.

"The one thing that gives me hope that sharks won't go extinct is because these animals are highly mobile and can swim thousands of kilometers a year," Lowe said. "Even though there's a lot of fishing going on, they may not be able to catch every single shark if we do a better job at regulating our fisheries or coming up with new ways of fishing that are more selective."

Established in 1999, the California Marine Life Protection Act led the state to increase coherence and effectiveness in protecting its marine life, habitats, marine ecosystems and marine natural heritage. The MLPA also provides minimal human disturbance and helps sustain, conserve and protect marine populations while also including species of economic value.

Lowe explained that California fisheries have regulations to protect populations and ensure that fish are caught safely and properly delivered by fishermen.

Climate change has also affected marine life and organisms through ocean warming, which absorbs the excess heat from greenhouse gas emissions that raise water temperatures.

According to Doug Pace, a CSULB marine biology professor, ocean warming and ocean acidification correlate because of "more carbon dioxide being trapped in the atmosphere" and oceans absorbing more carbon dioxide.

"We would expect on a global level both of them to increase with some predictable pattern, and the thing to keep in mind is that we've always mentioned on a global level," Pace said. "On average, carbon dioxide will cause an increase in ocean temperature, as well as an increase in acidity or decrease in pH levels, climate is talking about, you know, these really general trends over large areas."

As the climate's future remains uncertain, the ocean has become heavily impacted by the increase in carbon dioxide and other greenhouse gas emissions from human activities.

According to the International Union of Conservation for Nature, climate change has weakened the ocean and its coasts to provide necessary ecosystem services such as food, carbon storage, oxygen and nature-based solutions to help climate change adaptation.

Pace said that carbon dioxide is an important variable as much of it is being put into the atmosphere, which correlates "with increase in global temperature."

"Our climate models can only accurately predict the changes in climate we are seeing if we include the large amount of carbon dioxide being pumped into the atmosphere by way of fossil fuel use," Pace said.

This article was updated on April 19 at 9:40 p.m. to clarify information stated by Pace.