California Sea Lion Population Case Study

In Astoria, Oregon, invasive colonies of California Sea Lion have become overpopulated causing depleted populations of native fish, economical issues for the coastal city and they have caused immense damage to the docks. Due to the destructive nature of this invasive species on this ecosystem it becomes necessary to determine what is the most effective way of deterring California Sea Lions from colonizing on the Astoria docks and shoreline. If we relocate the California Sea Lions then, there will be a larger consistent decrease in the sea lion population than when scare tactics were previously used.

Nature has a unique way of working, then the humankind comes and ruins it all. The California Sea Lion is feeding off a species on the endangered species list, The Salmon. The Salmon attempts to travel upstream thru the Bonneville Dam where the Sea Lion awaits them. The Sea lion then eat them not allowing them to travel upstream becoming a greater problem for the already endangered species.

HOW HAS HUMAN ACTIVITY IMPACTED THE DECLINE IN POPULATION OF THE MACQUARIE ISLAND ELEPHANT SEAL?

How the Lionfish was introduced is not clear, but it is speculated that either through aquarium trade and thoughtless fish owners releasing the fish, or from the ballast water from foreign ships, that the Lionfish has been introduced (National Park Service. “Lionfish”). Over the years Lionfish have had quite a negative effect on the ecosystems it

Most people would not appreciate a stranger walking into their home unannounced, taking their food, and making themselves at home. That is exactly what lionfish are doing along the Florida coastline. Lionfish are an invasive species that need to be contained. The reefs that they consistently invade off of the coast of the Florida are not the lionfish's natural habitat. This invasive species takes shelter and resources out of the reef that other species need to survive, and they destroy the environment around them. Humans have complicated the balance of the ecosystem by introducing lionfish, and now they need to help rectify the situation.

The panda of the sea is in danger. The local Southern Resident Killer Whale J,K, and L pods population is disintegrating quickly. This is due to habitat destruction, reproductive issues, and a limited food supply. All of these factors are causing the Southern Resident Killer Whale population in the Pacific Northwest to decrease drastically and now they are a species that is listed under the Endangered Species Act. According to whale researcher Ken Balcomb, “The SRKW population was declared Endangered under the US Endangered Species Act in 2005, and earlier this year it was listed as a “species in the spotlight” by NOAA for its lack of recovery since then”(Balcomb). With recent deaths of J28 and her calf J54, many whale activist have been pushing

Sea Lions were commonly hunted for their meat, fur and oil, which was used in a variety of ways including waterproof containers, clothing, kayaks and general tools (Turek, 2007). It is believe that by 1820, many seal populations had been completely reduced to ruins and some breading colonies, such as the Brass Strait had been completely destroyed. Although the population of Australian sea lions has increased in recent years, many species still remain heavily threatened by human interactions, predominately from commercial fishing operations, reduction in food supply due to human disturbance and oil and chemical spills which can cause disease across a species (Energy, undated). It is currently believed that there are only 9,000 to 12,000 sea lions in

On March 21st, our class went to the Monterey Bay Aquarium. The purpose of this trip was not only to explore Earth’s natural habitat’s, but it was also to gather information on our upcoming project and to gather information on how the community of St.Mary, affects the Monterey Bay Aquarium. The answer that we found out is one based off of what we eat. The Monterey Bay Aquarium released an app where it showed which type of seafood were lower in numbers than others. So, if plankton were very low in numbers, it is advised that we not fish for them or not eat as much of it. This shows based just off of what we eat, we can affect the numbers of in the ocean. Also, those plastic bags we buy at Target and Walmart, that we drop outside, drifts itself to the streams, which flow to rivers, which go to oceans, they are floating there, not doing much harm, until sea turtle comes by starts eating it, but gets tangled and choked in it, dies.

The area of research that I have selected is the effects of overfishing in the Sea Otter ecosystem off the coast of California. The effects caused by the fishing pressure on the ecosystem will have different outcomes, depending on the strength and the types of relationships of the organisms present. (4) Red Abalone populations have declined drastically, to the point of the abalone fishery collapse. Several factors have led up to the collapse including Withering Syndrome, where the organism loses the ability to attach itself to rocks, making it more susceptible to predation, or the organism can eventually wither and starve to death. Sea Urchins and Red Abalone are a part of the same ecosystem, and are competitors of each other.(5) Both organisms graze on macroalgae and are a primary food source for Sea Otters. Sea Otters occurred from the North Pacific Rim down to Baja California, Mexico, but now only occur in small isolated patches (9) It is understood that Sea Otter presence can characterize community structure, where they can control and determine the size of Sea Urchin and Red Abalone populations. In the absence of Sea Otters, “Urchin Barrens” are created from the overgrazing of macroalgae by Sea Urchin. In these areas the ecosystem have changed dramatically, due to the overfishing, or in this case the over hunting, of Sea Otters causing a trophic cascade.(7)In some areas, Sea Otters have been reintroduced, in other areas they were never removed, and in others they

Sexually mature females can mate year around and are often either pregnant or caring for young throughout their lifetime, and this creates ongoing energy demands that can be energetically exhausting (Chinn et al. 2016). Sea otter mating behavior is aggressive and can further inflict physiological and traumatic stress to females, thereby reducing their foraging efficiency. Other factors such as infections, disease, bio-toxin ingestion and anthropogenic disturbance can also decrease fitness among adult females and increase their vulnerability during reproduction (Chinn et al. 2016). As nearshore inhabitants, southern sea otters often live in close proximity to areas of high human population density in California. These nearshore waterways can be busy with recreational and commercial boating activity that can disturb sea otter populations. Increased disturbance may cause increased stress to the species. Sea otters are of great interest to people who wish to view them, and this is sometimes done up-close by boat or paddle craft. If this activity changes sea otter behavior in any way, it not only violates the Marine Mammal Protection Act, it can also have a negative impact on the species, especially adult females with pups. Additionally, a familiar list of human impacts, such as climate change, overharvest of marine resources, municipal runoff, and habitat degradation likely reduce fitness of marine mammals directly and indirectly. Sea otters can be indicators of the overall health of the nearshore ecosystem (Kreuder et al. 2003). The slow growth rate of the southern sea otter population may be an expression of nearshore ecosystem degradation in California resulting from the fur trade and explosion of human population in

Cetacean bycatch is an ongoing problem in the oceans of the world. Cetaceans are defined as whales, dolphins and porpoises(CBRC 1). Bycatch is “marine mammals that are “captured” but discarded”(Read 2). This happens when fishing industries are fishing for a certain type of marine animal and other marine animals are caught accidentally along with the intended catch. Many times, this leads to the death of the animal that was not meant to be caught, and the animal is tossed back into the ocean. This happens with all kinds of marine life, and it has caused the depletion of many different species. However, this is specifically bad for cetaceans, such as dolphins and whales, because they have such a long lifespan(Brown 2). They also take a very long time to mature(Brown 2). These factors make catching these animals very detrimental to the species as a whole because it takes longer for them to reach an age where they can reproduce(Brown 2). The population of many cetaceans have decreased exponentially. When there is someone watching the nets that cetaceans are accidentally caught in, many times they can be saved. However, there are only select few types of fishing methods that do this, and they are not of the prevalent fishing methods that produce cetacean bycatch. This is a problem because there is a connection between most living animals. If a certain part of the connection is eliminated, it will all fall apart. For example, the relationship between

Humans fish to survive and in doing so they will target specific species leading to overfishing. Sound pollution is causing issues with the wildlife of the ocean in how they communicate and move around. With human interaction comes trash which gets left in the ocean and affects many different species.

According to the United Nations, 17% of fish stocks worldwide are currently overexploited; 52% are fully exploited; and 7% are depleted. This means that only an estimated 20% of worldwide fish stocks are not already at or above their capacity(Seafarms, 2013). Catches of Pacific herring have decreased by 71% since the 1960s, with Atlantic herring catches falling by 63%. Atlantic Cod catches have fallen by 69% in the same time(Seafarms, 2013). These are just a few of many facts and statistics on the topic of overfishing. The effects of these statistics and facts impact people’s and animal's lives around the

Clover’s stance on overfishing may seem over dramatic, but Clover’s statement is correct in pointing out that the real danger to the ocean’s wildlife is overfishing. Overfishing is when fish and other sea animal populations are being depleted to the point that sea animals cannot keep up with being fished by reproduction. Fishing massive amounts is degrading the oceans, yet there are both developed and developing countries whose economies rely heavily on fishing.

Majestic animals that live in the ocean are rapidly dying and subsequently washing up on numerous shorelines that touch the Pacific Ocean’s waters. Disposal of a variety of toxins and damaging waste finding a path into our oceans are to blame for the deaths, which are largely preventable. Sharks, sea turtles, whales, dolphins and birds are just fraction of the marine life that are suffering because they are becoming sick or are dying of starvation. Their food sources are diminishing or disappearing as the cycle of destruction continues on down to the tiny, minute plankton that are the core of the food chain in the ocean. Contamination is causing the sudden increase of marine life deaths in the Pacific Ocean. The most recent reports of dead sea animals found washed up on shorelines don’t state scientific evidence of the cause of the mysterious deaths.