Marine Habitats and Communities Main Concepts Marine Habitats

Marine Habitats and Communities

Main Concepts – Marine Habitats Ø Physical environment where community of organisms live is called a habitat. Ø Combination of physical factors at any one geographic site constitutes a habitat Ø Marine habitats, or ocean zones, are classified by several criteria: light, distance from land, depth, bottom Ø Marine life is dependent on complex dynamic exchanges with its physical environment. Ø A number of physical factors have a controlling effect on marine life. Most critical are termed limiting factors

Habitat Classification Schemes Ø Intensity of Sunlight Ø Distance from Shoreline Ø Bottom vs. Water Column Ø Water depth to Bottom Ø Tide zone levels

Zones of Marine Environments

Classification by Depth of Sunlight Penetration 1. Euphotic - down to 70 meters 2. Disphotic – 70 to 600 meters 3. Aphotic – below 600 meters

Habitat Classification - Distance from Shore

Habitat Classification – Bottom Zones The Benthos

Living Conditions in Marine Habitats v Most hospitable in shallow ocean close to land v Least in deep, dark ocean v More nutrients close to land v Least nutrients far from land

Marine Life Communities

Marine Communities Main Concepts Ø Marine communities consist of populations of different species that live and interact together in a unique habitat Ø Every species within a community is specifically adapted to its habitat, having a unique lifestyle and interactive relationship with the rest of the community 1) Shared limiting physical factors ü Light, temperature, nutrients, food, protection, bottom conditions 2) Complex organism interactions ü Competition, predation, mutualism, symbiosis

Trophic Levels in Marine Communties v Marine food chains are arranged into tropic levels with the phytoplankton at the bottom (first tropic level), which has the greatest numbers of individuals and greatest total biomass - more than all the other tropic levels put together. v It takes roughly 10 grams of phytoplankton to make 1 gram of zooplankton, and 10 grams of zooplankton to make 1 gram of tiny fish…and so on up the food chain.

Types of Marine Communities A. Intertidal Communities ü ü Rocky Beach Mud Flat Salt Marsh and Estuary B. Coastal Offshore Communities ü Kelp Forest ü Coral Reef ü Subtidal Shelf C. Open Ocean Pelagic Communities ü Shallow Pelagic ü Deep Pelagic ü Very Deep Pelagic D. Open Ocean Benthic Communities ü Abyssal ü Hydrothermal Vent ü Whale Carcass

Living Conditions in Marine Habitats v Most hospitable in shallow ocean close to land v Least in deep, dark ocean v More nutrients close to land v Least nutrients far from land

Rocky Intertidal Communities ü Intertidal communities live within one of the ocean’s most dynamic habitats – the shoreline ü Limited protection from waves and tides comes from purchase to a rocky substrate ü Vertical and lateral shifts in species assemblage occur within a community as a function of tidal influence

Rocky Intertidal Communities v. Zonation of the Benthal v Supralittoral: area just above high water mark, only submerged during storms; otherwise ocean spray v Littoral: intertidal zone between low and high water marks v Sublittoral: subtidal zone below water mark, permanently submerged; extends down to the continental shelf break (~200 m)

Rocky Intertidal Communities

Sand Cobble Beach Intertidal Communities ü Beach organisms must deal with perhaps the harshest of all marine conditions ü Pounding surf, shifting sand gravel, out-of-water exposure, and limited food supplies

Salt Marsh and Estuary Communities ü Salt marshes and estuaries are the most productive and biodiverse of all the marine communities ü Calm, nutrient-rich waters, protective habitat, and plenty of sunlight make for optimal living conditions ü Many open ocean organisms come here to spawn and nest ü Tidal flux and salinity are the two key dynamic factors

Salt Marsh and Estuary Communities

Kelp Forest Communities ü Kelp turns an otherwise barren offshore area into a haven for both pelagic and benthic organisms ü Kelp forests are very productive and support areas of high plant biomass and animal biodiversity. ü Kelp thrive best in cold, nutrient rich shallow waters up to 100 meters deep.

Kelp Forest Communities

Kelp Forest Creatures

Diving in Kelp Forest Communities

Coral Reef Communities ü Coral reefs are one of the most biodiverse regions in the ocean ü Coral reef systems are mostly limited to warm, clear, shallow tropical waters. ü Coral reef complexes provide both a food base and protection for a wide variety of invertebrates and fish. ü Coral reefs are inherently sensitive to environmental pressures

Open Ocean Communities

Pelagic Deep Sea Communities 1) Deep ocean organisms live in a very cold, high-pressure, pitch-black world. 2) Food and mates are very scarce, so deep-sea organisms have developed amazing feeding and mating strategies to deal with such harsh conditions. 1) Deep ocean organisms live in a very cold, high-pressure, pitch-black world.

Hydrothermal Vent Communities

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