Sei Whale
WHAT
ARE MY THREATS?
The DVD Case that Killed a Sei Whale
In August of 2014, biologists from the Virginia and Marine Science Center saw a 45-foot young female sei whale swimming up a river, far from its deep water oceanic home (Groc, 2015). They followed this disoriented whale, but despite their attempts to watch over her and keep her safe, she was found dead a few days later.
They discovered that the young sei whale had swallowed a rigid, black plastic shard (identified as a broken piece of a DVD case) that cut her stomach, which prevented her from feeding. The poor whale had also been struck by a ship and had a fractured vertebrae.
The tragedy of this young whale’s death was made even more heartbreaking due to the fact that her death was preventable. “Plastic ingestion is a widespread problem for marine mammals, particularly seabirds and turtles, which can easily confuse the debris for food” (Groc, 2015). The increasing amount of sea trash also increases the amount of dangers that marine life has to face. “Debris has been documented in 56 percent of cetacean species” (Groc, 2015). That debris fills up their stomachs, leaving no room for actual food like krill, and the whales slowly starve to death.
HIPPCO is an acronym for the greatest threats to marine biodiversity. Biodiversity is important because it boosts ecosystem productivity.
Habitat Loss
The sei whale is currently facing habitat loss in the sense that ocean temperatures are rising quickly, and the whale can only survive in warm waters to a certain extent (WWF, 2016). The sei whale prefers generally warmer waters because they're less predators, which is ideal for breeding. If our oceans continue to rise at their current rate, the sei whale will face even more habitat loss.
The sei whales live in the ocean, but the purity of the ocean is not what it used to be. Toxic chemicals from plastics, litter, oil spills, and chemicals like fertilizers and pesticides can build up in sei whales. The buildup of pollutants result in whales have less space to live and some die from these causes. The pollutants will accumulate in their bodies, eventually killing them. Even the runoff of pesticides from your lawn can get into the ocean, adding to the death rate of whales. The chemicals in the ocean may not only affect the whales but their food as well. The chemicals get into the whales' main food source, krill. Whales can consume up to forty million krill each day (WWF, 2020) as you can imagine, if the 40 million krill contain chemicals then the whales get sick faster and faster. Whales and their calves can even develop learning issues and thyroid issues as well. These pollutants can be passed to the calves through feeding from their mothers. (“Contaminants”) Along with all this, the sei whale can entangle themselves in abandoned fishing gear. Pollution is one of the forces pushing against the sei whale’s recovery.
This is not a huge threat to the sei whale, seeing as they are high up on the food chain. Their only predator is the orca whale. Due to the vastness of the oceans, the sei whale is able to survive in many different areas, so sharing ocean space with other creatures is not considered a big threat.
The sei whale can thrive in almost all ocean conditions, with the exception of arctic regions. However, as water temperatures warm, it becomes more and more difficult for them to survive in these waters. As their adequate environment decreases, there is less and less space for the species to live if numbers recover. Along with this, climate change may also lead to a fall in the population of krill, a primary food source (WWF, 2016).
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“Sei whales stay closer to the surface of the water and can eat about 900 kg per day! (NOAA, 2019)”
Population Growth
With a very low population of 152,000 (WWF, 2020), the sei whale is in desperate need of an increase. However, due to the limiting factors the whale population cannot rise quick enough.
Overfishing is one of the most impactful aspects of the sei whale endangerment. The are harmed by both commercial whaling and accidental fishing accidents.
