Southern Sea Otter Overview

Southern Sea Otter

• Southern sea otters, also known as California sea otters, live in the waters along the central California coastline.
• They use rocks to dislodge prey and open shellfish, making them one of the few mammals to use tools.
• Their diet consists primarily of marine invertebrates like sea urchins, mollusks, crustaceans, and some fish.
• Unlike most marine mammals, sea otters lack blubber and rely on a thick fur coat for warmth.
• Sea otters' high metabolic needs require consuming at least 20% of their body weight daily.
• They are a keystone species, controlling sea urchin populations.
• Historically, their population was estimated at 150,000-300,000 but was hunted extensively, reducing their numbers to 1,000-2,000 individuals.
• Their population increased between 1938 and 2009, rising from 50 to 2790, but they remain endangered.

Species Interactions

• Mutualism: A relationship where both species benefit. Examples include the partnership between nitrogen-fixing bacteria and leguminous plants, and the symbiotic relationship between anemonefish and sea anemones.
• Commensalism: A relationship where one species benefits and the other is neither harmed nor benefited. Examples include nurse plants offering protection to seedlings.
• Parasitism: A relationship where one species (the parasite) benefits, and the other (the host) is harmed.
• Competition: A relationship where both species are harmed because they compete for the same resources. Intraspecific competition occurs between members of the same species; interspecific competition occurs between members of different species.
• Predation: A relationship where one species (predator) benefits and the other (prey) is harmed.

Kelp Forests

• Kelp are large brown algae (Phaeophyta) that live in cool, relatively shallow waters near the shore.
• Kelp forests support a high diversity of plants and animals, providing shelter, food, and protection.
• Kelp forest environments are impacted by natural factors like predators and climate change, as well as human activities.

Competition for Resources

• Competition is a relationship between organisms that strive for the same resources in the same location (e.g., food, water, space).
• Competition may be intraspecific (between members of the same species) or interspecific (between members of different species).

Resource Partitioning

• Resource partitioning helps different species utilize limited resources by using slightly different parts of a resource, or by using the same resource at different times or in different places.

Bacteria

• Most bacteria are not harmful and some are helpful; such as gut bacteria which keep us healthy.

Parasitism

• Parasitism is a relationship where one organism (the parasite) benefits by deriving nutrition from its host, and the host is harmed.

Lamprey

• Lampreys use a rough tongue to consume prey's blood and body fluids.

Sea Otter Prey

• Sea otters prey on a variety of marine organisms, including fish, crustaceans, and mollusks.

Keystone Species

• Sea otters are keystone species that control sea urchin populations.

MCQ Answers

• (Note: The provided MCQ answers are not complete. You will need the full question to provide the best answer.)*

Explore the fascinating life of the Southern sea otter, including its unique behaviors, diet, and role as a keystone species. Find out about their history, population changes, and why they are considered endangered. This quiz delves into the ecological relationships involving these remarkable marine mammals.