Marine Biology Exam 2 Prep

a subphylum of chordates characterized by having a backbone or spinal column made of vertebrae, providing structural support and protecting the spinal cord.

includes cartilaginous fish like sharks and rays. They have skeletons made of cartilage instead of bone.

• Irrigate gills by swimming and opening and closing their mouths, spiracle also allow water intake

• internal fertilization

• 900 species

Most species are ovoviviparous, with embryos developing inside the mother's body and hatching internally before birth.

• internal fertalization

Relatively little shape or feeding style variation within a group

A class of bony fish characterized by a skeleton made of bone rather than cartilage, including most fish species.

• 23,000 species (most marine)

Enormous variety in shape, size, feeding style, behavior, habitat, locomotion

Irrigate gills by pumping, using their mouth, pharynx, and opercula

Osteichthyes reproduce through external fertilization. Most lay eggs, but some give live birth. They exhibit a variety of mating behaviors to reproduce.

• Reproduction generally involves spawning both eggs and sperm into the water column, although some fish guard eggs laid on the substratum or even on the bodies of the males

40% and because seperation allows for speciation

Sharks are cartilaginous fish with streamlined bodies, sharp teeth, and powerful jaws. They are apex predators in marine ecosystems.

Rays in chordates are supporting structures made of cartilage or bone found along the body, providing stability and protection.

• filter feed and are good at blending in with their habitat

Cartilage is a flexible connective tissue found in the body, while the bony skeleton is made up of hard, calcified bones providing structure and support.

• Includes animals with a backbone or spinal column

• Examples: mammals, birds, reptiles, amphibians, and fish

Flashcard: Reptilia - Class of vertebrates characterized by scales, cold-bloodedness, and laying eggs on land. Includes snakes, lizards, turtles, and crocodilians.

Flashcard: Class Aves are warm-blooded vertebrates with feathers, beaks, and lay eggs. They have lightweight bones and are adapted for flight.

• only 1% are marine

• body covered with dry scales

• eggs have leathery shells

• body temperature varies with that of the environment

• the only marine representatives are 7-8 species of sea turtles, 60 sea snake species, a marine iguana and a marine crocodile

Birds belonging to the class Aves that primarily inhabit marine environments, such as seabirds and shorebirds.

1. body covered with waterproof feathers

2. eggs have hard shells, and sea birds nest on land

3. body temperature regulated

4. hollow bones

5. marine birds consume huge amounts of high quality protein, mostly fish, but in a few cases plankton

penguins, tubenoses (albatrosses, petrels, and shearwaters), pelicans, gulls, terns; and there are many other groups of birds that inhabit the edge of the sea, such as egrets, ducks, herons, sandpipers, and plovers

Animal class characterized by hair or fur, mammary glands, and warm-bloodedness. Includes humans, dogs, and whales.

Mammalia Class - marine vertebrates. Adapted to aquatic life, breathe air, give birth to live young, have fur or hair, and mammary glands for nursing offspring.

1. body covered with hair

2. embryos nourished through a placenta and born live (in most cases)

3. body temperature regulated

4. mammary glands for nourishing young

Includes whales, dolphins, and porpoises. They are marine mammals with streamlined bodies, flippers, and a blowhole for breathing.

• Suborder Mysticeti: Baleen whales

• Suborder Odontoceti: Toothed whales

• Cetaceans are fully aquatic marine mammals

• Adaptations for swimming: streamlined bodies, flippers, flukes

• Echolocation used by some species for navigation and hunting

Order Sirenia includes manatees and dugongs, herbivorous marine mammals with paddle-like flippers and a unique body structure adapted for an aquatic lifestyle.’

• Order: Sirenia

• Characteristics: Aquatic herbivores, streamlined bodies

• Examples: Manatees, dugongs

• Habitat: Coastal waters, rivers, estuaries

• Conservation status: Vulnerable to extinction

Flashcard: Order Carnivora includes carnivorous mammals like lions and wolves, characterized by sharp teeth and claws for hunting and eating meat.

• marine: sea otter, polar bear

• Family: Felidae (cats), Canidae (dogs)

• Characteristics: Carnivorous, sharp teeth, claws

• Habitat: Diverse habitats worldwide

• Behavior: Solitary or social hunting

• Examples: Lions, tigers, wolves, bears

Flashcard: Order Pinnipedia - Group of marine mammals including seals, sea lions, and walruses. They have streamlined bodies and limbs adapted for swimming.'

• Family: Otariidae (eared seals), Phocidae (earless seals)

• Characteristics: Semi-aquatic marine mammals

• Examples: Sea lions, fur seals, elephant seals

• Habitat: Found in both polar regions and tropical areas

• Diet: Fish, squid, crustaceans

dN/dT = rN (K-N)/K

population size, intrinsic rate of increase, and carrying capacity

when N is very small, the population growth rate is close to exponential

dN/dT=rN(K)/K=rN

when the population size has reached its carrying capacity, the population growth rate is zero

dN/dT=rN(0)/K=0

no

1. number of offspring

2. size of offspring

3. semelparity vs. iteroparity

4. reproductive effort

5. age of first reproduction

6. timing of reproduction

• taking reproduction and mortality at each age into account

Direct development is a widespread alternate reproductive mode in living amphibians that is characterized by evolutionary loss of the free-living, aquatic larval stage

• A direct development is a type of development in which a young is directly born as a small version of an adult and it develops into a mature individual without undergoing metamorphosis.

lecithotrophy means feeding on egg yolk or other materials put in the egg by the mother; these larvae do not feed on anything else until after they settle to the bottom and become nonplanktonic juveniles.

• Lecithotrophic species produce fewer but larger eggs. These large yolky eggs develop into non-feeding larvae which usually lack feeding structures (e.g. mouth, gut, ciliary bands for capture of food particles). Lecithotrophic larvae spend comparatively less time in the plankton, and begin to feed after metamorphosis.

Planktotrophic larvae feed while they are in the water column and can be over a long time pelagic and so disperse over long distances.

• Planktotrophic larvae feed on phytoplankton and small zooplankton, including other larvae.

• Planktotrophy, meaning “feeding on plankton” refers to development via a larva that must feed in the plankton in order to develop to metamorphosis.

• Species with planktotrophic development produce many small energy-poor eggs with adequate nutrient reserves for the development of a feeding larva. These larvae must begin to feed immediately upon acquisition of feeding structures since they rapidly deplete their relatively insignificant yolk stores.

is a type of reproduction where parents provide care for their offspring, ensuring their survival and well-being.

Asexual propagation involves taking a part of one parent plant and causing it to regenerate itself into a new plant. The resulting new plant is genetically identical its parent. Asexual propagation involves the vegetative parts of a plant: stems, roots, or leaves.

• ex) starfish/ sea anemone

particular sets of life history traits often occur together because limited energy and time, as well as particular morphological and physiological characteristics, impose constraints (e.g., large number of offspring and large

K-selected species are those that are larger, have long lifespans, produce few young at a time, and exhibit logistic growth. R-selected species are those that have shorter lifespans, are generally smaller, produce many young, and exhibit exponential growth.

] "Logistic growth" is a type of population growth where the growth rate decreases as the population reaches its carrying capacity due to limited resources.

Exponential growth is a rapid increase where the quantity doubles at a constant rate over a period of time. It is often represented by a J-shaped curve on a graph.- -

• Exponential growth is a rapid increase in a population, where the number of individuals doubles in a fixed period.

• physical/chemical environmental conditions

• interactions among species:

Competition is an interaction between organisms or species in which both require a resource that is in limited supply. Competition lowers the fitness of both organisms involved since the presence of one of the organisms always reduces the amount of the resource available to the other.

• (-/-)

Predation involves one organism hunting and consuming another for food, while parasitism involves one organism living off another, harming it in the process.

• (-,+)

Mutualism is a type of symbiotic relationship where both species benefit from the interaction.

• An example of mutualism is the relationship between bees and flowers, where bees get nectar and pollen for food, while flowers get pollinated.

• variable, unpredictable

• variable, below K

• short

• repid development, early reproduction, small body size, semelparity

Reproductive strategy where an organism breeds once in its lifetime, investing heavily in offspring production, like salmon spawning and then dying.

• constant, predicatble

• constant, around K

• long

• slow development, delayed reproduction, large body size, iteroparity

Reproductive strategy where organisms produce offspring multiple times throughout their lifespan, increasing chances of survival and genetic diversity.

Rate of increase of population per unit of time (dN/dt) = Innate capacity for increase (r_max) x Population size (N) x Unutilized opportunity for growth (K-N / K).

• dN= change of number of inidviduals in a population

• dt= change in time

• N= number of individuals

• r= biotic potention, intrinsic rate of increase

• K = carrying capasity

Examples of marine Semelparity individuals include Pacific salmon and some species of octopus.

Examples of marine Semelparity individuals include Pacific salmon and deep-sea anglerfish. Deep-sea anglerfish are fascinating creatures that inhabit the dark depths of the ocean. These fish have a unique reproductive strategy where females possess a bioluminescent lure on their heads to attract prey. They are known for their extreme sexual dimorphism, where males are much smaller than females and often fuse to the female's body to reproduce. Deep-sea anglerfish exhibit semelparity, meaning they only reproduce once in their lifetime before dying. This reproductive strategy is crucial for their survival in the harsh environment of the deep sea, where resources are scarce and unpredictable. By investing all their energy into a single reproductive event, deep-sea anglerfish maximize their chances of passing on their genes to the next generation.

Examples of marine iteroparity individuals, which refers to organisms that can reproduce multiple times throughout their lives, are abundant in the ocean. Some notable examples include the Pacific salmon (Oncorhynchus spp.), which migrate from freshwater rivers to the ocean and back to spawn multiple times during their lifetime. Another example is the green sea turtle (Chelonia mydas), known for its long migrations between feeding and nesting grounds, where females return to lay eggs multiple times in a season. Additionally, the humpback whale (Megaptera novaeangliae) is a well-known marine mammal that exhibits iteroparity, as females give birth to calves every 2-3 years after a gestation period of around 11 months. These examples showcase the diverse range of marine species that demonstrate iteroparity as a reproductive strategy, allowing them to contribute to the next generation multiple times in their lives.

Well provisioned but no parental care, extended parental care, full care until born 

]Eggs and sperm are produced at different times in the reproductive cycle to maximize the chances of successful fertilization.

Internal Fertilization: The union of egg and sperm inside the body of one of the mating individuals.

Survival rate/birth rate: The ratio of individuals surviving to reproductive age compared to the number of births in a population during a specific period.

Reproductive value of an individual of age: The expected future offspring contribution of an individual at a specific age, considering mortality and fertility rates.

MYBPs are proteins that interact with MYB transcription factors, regulating gene expression and playing crucial roles in cell growth, differentiation, and development.

co-occurring species; all competitive, predatory, and mutualistic interactions between pairs of species are embedded in a more or less complex web of other interactions

1. types of organisms (e.g., taxonomic categories, growth forms, feeding types, reproductive strategies)

2. standing biomass

3. productivity (i.e., rate of production)

4. diversity - how many species, relative abundance of species

5. species accumulation curves – useful for determining if a community has been sampled adequately (with respect to number of species) and also for comparing between communities

1. energy flow pathways

   1. connectedness food webs

   2. energy flow food webs

   3. functional food webs

   4. number of levels

2. keystone species

3. succession – dynamics of community change

   1. efficient colonizers

   2. later recruiting, but good at persisting

• connectedness web

• energy flow web

• functonal web

Standing biomass refers to the total weight of living organisms (plants, trees) in a specific area at a given time, excluding roots and underground parts.

Rate of production is the speed at which new individuals are being produced in a population over a certain period of time.

"Diversity in marine biology refers to the variety of species, genetic differences within species, and ecosystem complexity within marine environments."

Species accumulation curves show the number of new species found as more individuals are sampled in an area, helping estimate total species richness.

Flashcard: Species accumulation curves show how the number of species increases with the number of individuals sampled in a specific area or habitat.Species accumulation curves are a valuable tool used in ecology to visualize how the number of species discovered increases as more individuals are sampled in a particular area or habitat. These curves provide insights into the biodiversity of an ecosystem and help researchers estimate the total number of species present. By plotting the cumulative number of species against the number of individuals sampled, scientists can observe patterns such as species richness and evenness. This information is crucial for conservation efforts and understanding the dynamics of species distribution within an ecosystem. Additionally, species accumulation curves can reveal whether further sampling is likely to uncover new species or if the majority of species present have already been identified. Overall, these curves offer a glimpse into the complexity and diversity of life within a given environment, shedding light on the intricate relationships between different species and their surroundings.

Energy flow pathways in biology refer to the routes through which energy is transferred between organisms in an ecosystem, typically following a unidirectional flow from producers to consumers and decomposers.

Connectedness food webs are complex networks that illustrate the flow of energy and nutrients between different species in an ecosystem.

Energy flow food webs illustrate the transfer of energy from one organism to another within an ecosystem, showing the direction of energy flow.

Functional food webs depict the flow of energy and nutrients in an ecosystem, showing the interconnections between different organisms and their roles in maintaining the ecosystem's stability.

Connectedness food webs show how species are connected through interactions, energy flow food webs illustrate the transfer of energy between species, and functional food webs focus on the roles species play in an ecosystem.

Keystone species are organisms that have a disproportionately large impact on their ecosystem relative to their abundance.

"Succession in biology refers to the process of ecological change in a community over time, transitioning from one type of ecosystem to another."

Efficient colonizers in biology are species that quickly establish and dominate new habitats, outcompeting native species for resources and space.

Later recruiting species are organisms that colonize an area after the early successional species have established, contributing to further ecosystem development.

Rocky substrata are hard surfaces like rocks where organisms attach and grow, providing habitats for various marine species.

• Rocky substrata constitute only a small portion of intertidal habitats, but the ease of viewing exactly what is living in a particular area has resulted in

  disproportionately important contributions to population and community ecology from experiments done in this habitat.

• rock

• waves

• tides - exposure to air

• habitat fragmentation

Habitat fragmentation occurs when large habitats are divided into smaller, isolated pieces, leading to a loss of biodiversity and disruption of ecosystems.

"Competition for space among sessile plants and animals in rocky substrata occurs due to limited attachment sites and access to resources like light and nutrients."

Readily observed zonation is the distinct pattern of plant and animal communities in different environmental conditions along a gradient, easily noticeable in ecosystems like intertidal zones.

experimental investigation of the balance between competitive interactions and resistance to physical challenges and predators

• Joe Connell's rocky substrata experiments demonstrated that species distribution is influenced by competition for space, leading to zonation patterns.

Predators impact zonation by controlling prey populations, affecting competition for space, and promoting species diversity through their influence on ecosystem structure and interactions.Predators play a crucial role in shaping the dynamics of ecosystems through their interactions with prey species. By controlling prey populations, predators help regulate the balance of species within different zones of an ecosystem. For example, in a marine environment, the presence of predators can prevent certain prey species from overpopulating and outcompeting others for resources such as food and habitat. This control over prey populations can lead to a more diverse community of species coexisting within the ecosystem.

Furthermore, the influence of predators on prey behavior can also impact the distribution of species within different zones, creating distinct patterns of spatial organization. For instance, in a forest ecosystem, the presence of predators can lead to prey species avoiding certain areas where the risk of predation is higher, thereby creating zones of relative safety that can influence the overall structure of the ecosystem.

Overall, the intricate interactions between predators and prey contribute to the richness and complexity of ecosystems, highlighting the interconnectedness of species within different zones and the importance of maintaining a balance between predator and prey populations for the overall health and stability of the ecosystem.

•  experimental investigation of how predation can increase the number of species in a community

Bob Paine (1966) introduced the concept of keystone species, which have a disproportionately large impact on their ecosystem relative to their abundance.Bob Paine, an American ecologist, made a groundbreaking contribution to the field of ecology in 1966 by introducing the concept of keystone species. These species play a crucial role in maintaining the balance and diversity of their ecosystems, despite their often low abundance. Paine's research highlighted that certain species, even if they are not the most numerous in an ecosystem, can have a significant impact on its structure and function. By focusing on keystone species, ecologists can better understand the intricate web of interactions within an ecosystem and the cascading effects that can result from the loss or decline of a key species. Paine's work emphasized the importance of looking beyond just the most abundant or obvious species in an ecosystem and considering the broader implications of individual species on the health and stability of the environment. This concept has since become a fundamental principle in ecology and has influenced conservation efforts aimed at protecting keystone species to preserve the overall biodiversity and functioning of ecosystems.

3 predators with counter-intuitively overlapping prey consumption patterns; there is no substitute for understanding the organisms and their habitats

Paul Dayton (1973) experiment - Research on kelp forest ecology, demonstrating the importance of sea otters in maintaining ecosystem balance by controlling sea urchin populations.Paul Dayton's groundbreaking experiment in 1973 focused on researching kelp forest ecology, shedding light on the crucial role of sea otters in maintaining ecosystem balance. Through his study, Dayton illustrated how sea otters play a vital role in controlling sea urchin populations, which in turn has a significant impact on the overall health and stability of the kelp forest ecosystem. By preying on sea urchins, sea otters prevent these herbivores from overgrazing on kelp, thus preserving the delicate balance within the ecosystem. Dayton's research highlighted the intricate interconnections within marine environments and emphasized the cascading effects that can occur when key species, such as sea otters, are removed from the ecosystem. This experiment not only deepened our understanding of the complex relationships in kelp forests but also underscored the importance of conserving keystone species like sea otters to ensure the resilience and sustainability of marine ecosystems.

Caution about overly facile generalizations - Warns against making simplistic or hasty conclusions without considering all relevant factors or complexities.

Effects of physical disturbance on competition, colonization, succession, and diversity: Physical disturbances can alter species interactions, colonization rates, and succession pathways, impacting community diversity.

Physical disturbances impact competition, colonization, succession, and diversity by altering resources, habitats, and species interactions in ecosystems.

Intermediate Disturbance Hypothesis proposes that moderate levels of disturbance promote species diversity by preventing competitive exclusion and allowing for colonization opportunities.

Connell 1978 experiment: Investigated the impact of predator presence on the diversity of prey species in intertidal ecosystems. Found that the removal of predatory starfish led to an increase in the number of prey species, demonstrating the role of predators in maintaining biodiversity.

Life history strategies influence diversity peaks at intermediate disturbance levels. Organisms with different strategies thrive in varying disturbance levels, contributing to overall biodiversity.

Life history strategies determine diversity peaks at intermediate disturbance levels.Life history strategies play a crucial role in shaping the diversity peaks observed at intermediate disturbance levels within ecosystems. These strategies encompass a wide range of adaptations and behaviors that organisms employ to survive and reproduce in their environments. For instance, some species may exhibit r-selected traits, such as high reproductive rates and small body sizes, allowing them to quickly colonize disturbed habitats. On the other hand, other species may display K-selected traits, including larger body sizes and longer lifespans, which provide a competitive advantage in more stable environments. The interplay between these different life history strategies influences how species respond to disturbances of varying intensities. At low disturbance levels, K-selected species may dominate due to their competitive abilities and efficient resource utilization. Conversely, at high disturbance levels, r-selected species may thrive by rapidly exploiting available resources and outcompeting slower-growing competitors. However, at intermediate disturbance levels, a balance is struck where neither extreme strategy has a clear advantage, leading to a peak in species diversity. This dynamic relationship underscores the importance of considering the diverse ways in which organisms have evolved to cope with environmental changes and highlights the intricate connections between life history strategies and ecosystem dynamics.

Rocky shores form from the gradual accumulation of rocks and boulders along a coastline, often due to erosion, sediment deposition, and tectonic activity.

1. inter-tidal, temperate and sub-arctic, estuaries and sheltered coasts

2. distinct zones, each dominated by a grass species with its lower boundary determined by physiological stress and the upper by competition

3. capture and bind sediment flowing off the land, and transform dissolved inorganic nutrients to particulate organic materials

4. dominant grasses propagate clonally by rhizomes

5. terrestrial, aerial, and marine consumers

Salt marshes are coastal ecosystems characterized by salt-tolerant plants. They provide habitat for diverse wildlife, protect coastlines from erosion, and filter pollutants from water

Salt marshes are coastal ecosystems found in intertidal areas where saltwater and freshwater mix. These unique habitats are characterized by the presence of salt-tolerant plants such as Spartina alterniflora, also known as smooth cordgrass, and Salicornia, commonly referred to as pickleweed. These plants have adapted to thrive in the saline conditions of the marsh environment.

One of the key functions of salt marshes is providing essential habitat for a wide range of wildlife, including birds, fish, and invertebrates. Many species rely on salt marshes for nesting, feeding, and shelter, making these ecosystems crucial for maintaining biodiversity along coastlines.

In addition to supporting diverse wildlife, salt marshes play a vital role in coastal protection. The dense network of plant roots helps stabilize sediments and reduce erosion caused by waves and tides. By acting as a natural buffer, salt marshes help protect coastal communities from the impacts of storms and sea-level rise.

Furthermore, salt marshes serve as natural filtration systems, helping to improve water quality by trapping and removing pollutants. As water flows through the marsh, plants and sediments capture excess nutrients and contaminants, preventing them from entering the larger aquatic ecosystem. This filtration process not only benefits the local environment but also contributes to the overall health of coastal waters.

Overall, salt marshes are invaluable ecosystems that provide a wide range of ecological services, from supporting wildlife and protecting coastlines to purifying water. Preserving and restoring these habitats is essential for maintaining the health and resilience of coastal environments worldwide.

1. shallow sub-tidal, temperate and tropical

2. no distinct zones, often a few species of "grasses" live intermingled with each other and also with macro-algae

3. blades can be heavily covered by epiphytes

4. seagrass plants propagate clonally by rhizomes

5. long, and sometimes straggly, blades are thought to be a problematic result of the loss of large herbivores such as green turtles, manatees, and dugongs

Seagrass meadows are underwater ecosystems made up of flowering plants that provide habitat for various marine species. They also help stabilize coastlines and improve water quality.Seagrass meadows are vital underwater ecosystems teeming with life and biodiversity. These unique habitats are composed of flowering plants that create a lush underwater landscape, offering a safe haven for a wide range of marine species. From small fish and crustaceans to sea turtles and manatees, seagrass meadows support a diverse array of organisms, forming a complex web of interactions beneath the waves.

In addition to their role as marine sanctuaries, seagrass meadows play a crucial role in coastal ecosystems by helping to stabilize shorelines. The dense root systems of seagrass plants trap sediment and reduce erosion, protecting coastlines from the damaging effects of waves and currents. Furthermore, seagrass meadows contribute to improving water quality by absorbing nutrients and filtering out pollutants, thereby enhancing the overall health of the marine environment.

Overall, seagrass meadows are not only breathtaking underwater landscapes but also essential ecosystems that support marine life, safeguard coastlines, and promote water quality in our oceans.

1. inter-tidal, tropical and sub-tropical

2. distinct zones, each dominated by a single mangrove species

3. trees - that do not propagate clonally; each needs to sprout from a seed, and the seeds sprout while still on the mother tree

4. prop roots are heavily epiphytized, with an extremely species-rich community of invertebrates and plants

5. sponges on the roots can protect them from boring crustaceans that can cause death of the trees

Coastal trees or shrubs growing in brackish water with unique root systems that help protect shorelines and provide habitats for diverse marine life.Coastal trees or shrubs play a crucial role in the fragile ecosystem of brackish water environments. These specialized plants have adapted to thrive in the challenging conditions of fluctuating salinity levels. Their unique root systems, such as mangroves' prop roots or salt marsh grasses' rhizomes, serve as a natural defense mechanism against erosion, helping to stabilize shorelines and prevent land loss due to waves and tides. Additionally, these root systems create intricate networks that provide habitats for a wide range of marine and bird species, contributing to the overall biodiversity of coastal regions. By acting as a buffer between land and sea, coastal trees and shrubs not only protect the coastline from erosion but also filter out pollutants and sediment, improving water quality and supporting the health of surrounding ecosystems. The presence of these plants is essential for maintaining the balance and resilience of coastal areas in the face of environmental challenges such as sea-level rise and storm surges.

1. relatively low species diversity of the structure-providing plants

2. but often high species diversity of the organisms living among the structure- providing plants

3. high productivity

4. relatively few organisms feed directly on the living plant parts

5. intercept sediments and nutrients flowing off the land

6. play important roles in the functioning of adjacent ecosystems, contributing food and also shelter during vulnerable times of day or for especially vulnerable (generally juvenile) life stages, i.e, serving as 'nursery habitats'

7. besieged by destructive human activities that are often motivated by misunderstandings of the extreme value of these ecosystems

Kelp forests are underwater ecosystems dominated by large brown algae called kelp. They provide habitat and food for various marine organisms.

• kelps are primarily cold-water organisms, capable of growing extremely rapidly (productivity as high as 5400 gm C/m2/yr) in nutrient rich water; unlike many tropical brown algae, kelps do not appear to be chemically defended against herbivores; kelp stipes can be as long as 100 ft!

sea otters are in the Order Carnivora, and do not have blubber, requiring that they consume up to 25 -30 percent of their body weight each day to maintain body temperature and grow, reproduce, etc.; their extraordinarily dense fur helps to insulate them, with air bubbles among the hairs

the large kelp plants are the sporophyte generation, and the gametophyte is microscopic, with very different morphology and requirements; dependence on high nutrient levels makes kelps vulnerable to mass mortality during El Niño years; and their enormous size can make them vulnerable to being ripped off the bottom and cast ashore during storms; lack of chemical defenses makes them vulnerable to herbivores