Marine biology is the scientific study of the biology of marine life, organisms in the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy.
The littoral zone or nearshore is the part of a sea, lake, or river that is close to the shore. In coastal environments, the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged. The littoral zone always includes this intertidal zone, and the terms are often used interchangeably. However, the meaning of littoral zone can extend well beyond the intertidal zone.
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "the depths." Organisms living in this zone are called benthos and include microorganisms as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud.
Kelp forests are underwater areas with a high density of kelp, which covers a large part of the world's coastlines. Smaller areas of anchored kelp are called kelp beds. They are recognized as one of the most productive and dynamic ecosystems on Earth. Although algal kelp forest combined with coral reefs only cover 0.1% of Earth's total surface, they account for 0.9% of global primary productivity. Kelp forests occur worldwide throughout temperate and polar coastal oceans. In 2007, kelp forests were also discovered in tropical waters near Ecuador.
The intermediate disturbance hypothesis (IDH) suggests that local species diversity is maximized when ecological disturbance is neither too rare nor too frequent. At low levels of disturbance, more competitive organisms will push subordinate species to extinction and dominate the ecosystem. At high levels of disturbance, due to frequent forest fires or human impacts like deforestation, all species are at risk of going extinct. According to IDH theory, at intermediate levels of disturbance, diversity is thus maximized because species that thrive at both early and late successional stages can coexist. IDH is a nonequilibrium model used to describe the relationship between disturbance and species diversity. IDH is based on the following premises: First, ecological disturbances have major effects on species richness within the area of disturbance. Second, interspecific competition results in one species driving a competitor to extinction and becoming dominant in the ecosystem. Third, moderate ecological scale disturbances prevent interspecific competition.
The intertidal zone, also known as the foreshore or seashore, is the area above water level at low tide and underwater at high tide. This area can include several types of habitats with various species of life, such as seastars, sea urchins, and many species of coral with regional differences in biodiversity. Sometimes it is referred to as the littoral zone, although that can be defined as a wider region.
Intertidal ecology is the study of intertidal ecosystems, where organisms live between the low and high tide lines. At low tide, the intertidal is exposed whereas at high tide, the intertidal is underwater. Intertidal ecologists therefore study the interactions between intertidal organisms and their environment, as well as between different species of intertidal organisms within a particular intertidal community. The most important environmental and species interactions may vary based on the type of intertidal community being studied, the broadest of classifications being based on substrates—rocky shore and soft bottom communities.
Joan Roughgarden is an American ecologist and evolutionary biologist. She has engaged in theory and observation of coevolution and competition in Anolis lizards of the Caribbean, and recruitment limitation in the rocky intertidal zones of California and Oregon. She has more recently become known for her rejection of sexual selection and her theistic evolutionism.
Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, seagrass meadows, mangroves, rocky intertidal systems, salt marshes, coral reefs, lagoons. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.
A shifting baseline is a type of change to how a system is measured, usually against previous reference points (baselines), which themselves may represent significant changes from an even earlier state of the system.
The wrack zone or wrack line is a coastal feature where organic material and other debris is deposited at high tide. This zone acts as a natural input of marine resources into a terrestrial system, providing food and habitat for a variety of coastal organisms.
Jeremy Bradford Cook Jackson is an American ecologist, paleobiologist, and conservationist. He is an emeritus professor at the Scripps Institution of Oceanography, senior scientist emeritus at the Smithsonian Institution, and visiting scientist at the American Museum of Natural History Center for Biodiversity and Conservation. He studies threats and solutions to human impacts on the environment and the ecology and evolution of tropical seas. Jackson has more than 170 scientific publications and 11 books, with nearly 40,000 citations listed on Google Scholar.
Robert Treat "Bob" Paine III was an American ecologist who spent most of his career at the University of Washington. Paine coined the keystone species concept to explain the relationship between Pisaster ochraceus, a species of starfish, and Mytilus californianus, a species of mussel.
Bruce A. Menge is an American ocean ecologist. He has spent over forty years studying the processes that drive the dynamics of natural communities. His fields of interest include: structure and dynamics of marine meta-ecosystems, responses of coastal ecosystems to climate change, linking benthic and inner shelf pelagic communities, the relationship between scale and ecosystem dynamics, bottom-up and top-down control of community structure, recruitment dynamics, ecophysiology and sub-organismal mechanisms in environmental stress models, larval transport and connectivity, impact of ocean acidification on marine ecosystems, controls of productivity, population, community, and geographical ecology. He settled on two career goals: carrying out experiment-based field research to investigate the dynamics of rocky intertidal communities, focusing on species interactions and environmental context and how this might shape a community, and using the resulting data to test and modify theories on how communities were organized.
Pollicipes polymerus, commonly known as the gooseneck barnacle or leaf barnacle, is a species of stalked barnacle. It is found, often in great numbers, on rocky shores on the Pacific coasts of North America.
A habitat cascade is a common type of a facilitation cascade. where “indirect positive effects on focal organisms are mediated by successive formation or modification of biogenic habitat”.
Seascape ecology is a scientific discipline that deals with the causes and ecological consequences of spatial pattern in the marine environment, drawing heavily on conceptual and analytical frameworks developed in terrestrial landscape ecology.
Lisa A. Levin is a Distinguished Professor of biological oceanography and marine ecology at the Scripps Institution of Oceanography. She holds the Elizabeth Hamman and Morgan Dene Oliver Chair in Marine Biodiversity and Conservation Science. She studies coastal and deep-sea ecosystems and is a Fellow of the American Association for the Advancement of Science.
Benthic-pelagic coupling are processes that connect the benthic zone and the pelagic zone through the exchange of energy, mass, or nutrients. These processes play a prominent role in both freshwater and marine ecosystems and are influenced by a number of chemical, biological, and physical forces that are crucial to functions from nutrient cycling to energy transfer in food webs.
A marine coastal ecosystem is a marine ecosystem which occurs where the land meets the ocean. Marine coastal ecosystems include many different types of marine habitats, such as estuaries and lagoons, salt marshes and mangrove forests, seagrass meadows and coral reefs, kelp forests and backwaters. Directly and indirectly these provide a vast range of ecosystem services for humans, such as sequestering carbon, cycling nutrients and elements, providing nurseries and fishing grounds for commercial fisheries, preventing coastal erosion and moderating extreme events, as well as providing recreational services and supporting tourism.
