Oceans are running out of oxygen. Since the 1960s, warmer waters & excess fertilizers from anthropogenic activities have resulted in a 2% drop in sea oxygen levels, wreaking havoc on marine life.
Sharks and Climate Change: Their Past and Present
Sharks have existed on the planet for nearly 450 million years and have grown to survive in all climates. Sharks in the past lived in oceans with greater than normal temperatures or acidities than today's oceans. Furthermore, today's sharks do not even have the luxury of adapting to new, harsh environments over many generations; instead, the quick change in sea temperature or acidity appears to be too much for the creatures.
How sharks are affected by climate change
Humans are profoundly changing climate by emitting greenhouse gasses, which impacts marine life in terms of coastal erosion, climate changes, water temperature, coastal erosion, ocean chemistry, sea level, currents, and storm frequency. Many of these effects have already been noticed, but experts predict that they will grow more severe if climate change continues. Changes to the foundation of the maritime environment, such as these, are likely to impact the food supply, distribution, migration patterns, reproduction, and interactions with other elements of the food web for marine species. These alterations may have an impact on animal behavior. Climate change is already underway, and it is only going to become worse before it improves. Even during this transition, we have no idea what to expect. Nonetheless, scientists undertake daily experiments and monitor how the earth's temperature and ecosystem change, providing us with additional information about what's going on and what to expect. This is particularly critical for species already endangered and face various stressors, such as sharks and rays, which meet both criteria.
The Threats that Today's Sharks Face
Sharks today confront numerous threats due to a quicker transition to a warm period caused by global warming. So, what exactly are these threats, and how do they affect sharks?
1. Climate Change and Reef Sharks
Sharks that live in coral reef environments are particularly vulnerable to global warming. Coral reefs and the ecosystem they sustain are at peril as the ocean warms, becomes more hazardous, and grows more acidic (owing to more carbon dioxide becoming absorbed by the water). If coral reefs start dying off as a result of rising temperatures or pH changes, or as a result of storms and are becoming more common due to climate change, sharks that live on these reefs will be at risk and possibly endangered.
2. Shark Migration is affected by Climate Change
Most people prefer it when the ocean is warm because it allows them to swim more easily. Unfortunately, many sharks are not as enthusiastic as we are. Sharks are changing their migratory patterns and routes as the waters warm to remain in the most pleasant waters. The Bull Shark is one shark species that has already altered its migratory patterns. Bull sharks are starting to show up in places they've never been before, and scientists claim it's due to warming waters. While this may appear to be trivial, it has a massive effect on oceanic ecosystems. Because Bull Sharks are near the top of the food chain, their entry into new places could disturb an otherwise well-functioning ecosystem. The bull shark might imperil everybody involved by posing a hazard to nursery areas or scaring rival predators out of the ecosystem altogether.
3. Impacts on Development
Studies on the impacts of climate change on sharks have revealed some intriguing developmental links. Sharks that have been subjected to warmer waters appear to have a reduced growth and reproduction rate. According to a study, rising ocean temperatures & carbon dioxide levels are impacting shark brain development, potentially altering behavior and decision-making abilities and resulting in smaller brains.