Benthos

Benthos Intertidal Zone Muddy bottom and sandy bottom communities Salt marshes and seagrass beds Coral reefs Deep ocean benthos

Intertidal Zonation Zonation is a vertical banding of the organisms living on the rocky coastline. These distinct bands occur in part from many complex physical and biological factors that effect marine organisms.

effect on marine organisms living in the intertidal zone? Which tidal cycle has the greatest effect on marine organisms living in the intertidal zone? Spring tide

Tidal Zones on a Rocky Ocean Shore Splash Fringe Level High Tide Level Mid Tide Level Low Tide Level Low Fringe Level

Mostly shelled orgs Spray or Splash Zone High Tide Zone Middle Tide Zone Many soft bodied orgs and algae Low Tide Zone

Big Island

periwinkles ulva opihi Mussels & starfish

that affect the organisms residing in the intertidal zone? What are some stresses that affect the organisms residing in the intertidal zone?

Biotic factors affecting organisms living in the intertidal zone: Competition for space and food Predation Reproduction Substrate settlement preference Osmoregulation

Abiotic factors affecting organisms living in the intertidal zone: Salinity Temperature Air and light exposure Tidal flow Waves and current action Substrate Wind direction and strength Dissolved O2 Storms Natural Disasters

What are some adaptations to living in the intertidal zone?

Muddy bottom and sandy bottom communities Infauna:  live within the sediment, mostly soft bottom;  mostly clams and worms (polychaetes)  burrow tubes for food scavenging and oxygen supply Orgs that live in the interstices of the sand

Muddy bottom and sandy bottom communities 32,000 polychaetes in sand/m2 vs 50-500 earth worms in soil/m2 Ecological Role: clean sediments aerate soil

Salt marshes

Salt marshes Found from the Arctic to Southern Australia Salt marshes grow in muds and sands that are sheltered by barrier islands. Flood and ebb currents transport saltwater, nutrients, plankton and sediments in and out of the marsh.

Zonation in Salt Marsh Species composition and zonation governed by: Salinity gradient: river runoff, tides Intertidal exposure Low species diversity Ribbed mussel Coastal salt marshes develop along the intertidal shores of bays and estuaries. Estuaries occur where a river meets the sea, and the water is somewhat brackish. In general, salt marshes along the Northern California coast have a relatively low salinity because of substantial river runoff, whereas those along the southern coast, where there are fewer rivers and less runoff, are of higher salinity. San Francisco Bay contains the largest and one of the most complex salt marsh systems in the state. Salt marsh plants are adapted to a harsh, semi-aquatic environment and saline soils. Species diversity is low. Stout stems, small leaves, and physiological adaptations for salt excretion and gas exchange characterize the inhabitants of the salt marsh, which are mostly grasses and low perennial herbs. The tangle of marsh plant roots and stems helps to stabilize the muddy bottom, as well as to trap debris and dissolved nutrients with each tidal cycle. Bacteria convert this oasis of detritus into food resources for microscopic algae, invertebrate larvae, and larger animals. Salt marshes are about twice as photo-synthetically productive as corn fields and provide critical nursery grounds for numerous organisms. Species composition and zonation in the salt marsh are governed by salinity gradients in combination with the amount of intertidal exposure. Eelgrass, Zostera marina, for example, occupies the lowest or most marine zone. It cannot tolerate a freshwater environment or intertidal conditions that would expose its roots to air. Cordgrass, Spartina foliosa, occurs in the marine-to-terrestrial transition zone, characterized by lower salinity and periodic exposure to the air. Shoreward, where conditions are even drier, pickleweed species belonging to the genus Salicornia are common. On higher ground, where tidal intrusions are rare, the wiry, prickly-leaved succulent jaumea, Jaumea carnosa, is common, as are the bushy shoregrass, Monanthochloe littoralis; tall and slender sea arrowgrass, Triglochin maritima; and endangered salt marsh bird's beak, Cordylanthus maritimus. The green, wiry-leaved saltgrass, Distichlis spicata, is widespread, occurring from the middle to high marsh, as well as in dunes and on salt flats. An unusual salt marsh plant is the orange, parasitic dodder, Cuscuta salina. Its tiny, scale-like leaves and thread-like stems frequently invade and cover large areas of vegetation. Fiddler crab

Salicornia Fundulus heteroclitus Distichles spicata

Hawaiian Stilt Hawaiian Coot The ae`o is an endemic subspecies of the black-necked stilt of North and South America. It is a small, slender, black and white bird with long pink legs. A wader, the ae`o is often seen in shallow water and mudflats foraging for aquatic insects, worms, crustaceans, and small fish. Ae`o nest from March through August in low-lying vegetation adjacent to natural and artificial water bodies. Nests are shallow depressions lined with stones, twigs, and other materials, and the average clutch is four eggs. The downy chicks are tan with black speckling. The adults defend their territories by feigning injury to detract potential predators from their nests and young. They will also give a loud, sharp call and fly nervously around their nests when disturbed. In traditional times - when the ae`o was common - it was eaten. People caught the birds by pelting them with stones. But populations of the ae`o and other waterbirds declined significantly after Western contact. Prior to humans arriving in the islands, large natural marshes and ponds occurred on most of the main Hawaiian islands. Native Hawaiian construction of fishponds along the coast and lo`i kalo (flooded taro patches) in the valleys resulted in the creation of additional waterbird habitat. Before Western contact, an estimated 25,000 acres may have been in kalo production. Changes in land tenure, the loss of Native Hawaiian land, and major stream diversions resulted in a decline in kalo production and the loss of waterbird habitat. By 1900, approximately 18,000 acres were in kalo production; by 1960, only 510 acres were being cultivated. Many wetlands were eventually filled, and hotels, subdivisions, golf courses, shopping centers, landfills, military bases, industrial areas, and agriculture have taken their place. Extensive wetland losses occurred at Mana on Kaua`i, Kanaha Pond on Maui, marshes in Waikiki, Mo`ili`ili, Moanalua, Kawainui, and Pearl Harbor, and Ka`elepulu and Kuapa ponds on O`ahu. In addition to the loss of habitat, ae`o are threatened by introduced predators, such as rats, mongooses, dogs, and cats, habitat degradation by invasive plants, diseases, pollution, loss of food sources, and human disturbance. Botulism, caused by a soil bacterium passed on to ae`o through contaminated food sources, kills large numbers of birds during occasional outbreaks. Infected birds are unable to use their legs or wings or hold their heads up, and eventually die. Until around 1940, hunting was yet another threat to ae`o and other waterbirds in Hawai`i. The ae`o was listed as an endangered species in 1970. The statewide population of some 1,200 to 1,600 birds is considered to be relatively stable or slightly increasing. Ae`o occur on Ni`ihau, Kaua`i, O`ahu, Moloka`i, Maui, Lana`i, and Hawai`i. The recovery of banded birds indicates that some ae`o move between the islands, especially between Ni`ihau and Kaua`i. The first reported occurrence of ae`o on Lana`i was made in 1989 at the Lana`i City wastewater treatment ponds. The Moloka`i population of ae`o appears to be increasing in recent years. Twenty ae`o were observed during the first annual Christmas count of ae`o on Moloka`i in 1989. The number has increased since then to 148 birds observed in 2001. The increase may be due to recent fishpond renovations along the coast and the creation of suitable habitat. Although ae`o tend to occur in the lowlands, they are occasionally reported from upper elevations. For example, ae`o were observed in June of this year foraging in the Pu`u Wa`awa`a reservoir on Hawai`i at approximately 2300 feet, and they are still occupying this habitat. One of the core breeding habitats for the ae`o on O`ahu is the Nu`upia Ponds Wildlife Management Area on Mokapu Peninsula. Active management of the habitat and surrounding environment is overseen by Dr. Diane Drigot, senior natural resources management specialist with the Marine Corps Base Hawai`i in Kane`ohe. Mangroves and other invasive plants have been removed from the wetland. Nesting islands for ae`o were created in the middle of the ponds to protect the birds from predators. Marines improve foraging habitat while conducting training maneuvers, predators are controlled, and school children learn about waterbird ecology and plant, weed, and monitor native riparian plants. Over the past 20 years, these efforts have resulted in a doubling of the stilt population at Mokapu from 60 to 130 birds. The base now provides habitat for nearly 10 percent of the state's total stilt population, as well as 49 additional taxa of waterbirds, seabirds, and shorebirds. The Corps is also contributing to the recovery of ae`o at a regional level. Sustainable Resources Group International, Inc., has been contracted to prepare a habitat protection plan for the district of Ko`olaupoko (windward O`ahu from Kualoa Point to Waimanalo). The environmental program at Mokapu and efforts by the Corps to help maintain a network of waterbird habitat in Ko`olaupoko are models for effective species conservation in Hawai`i. Found on all the main islands except Lanai Found on all the main islands

Waikiki & Diamond Head Changes in Waikiki The 1920s were a decade of change in Waikiki. The Ala Wai Canal was dredged and the duck ponds, taro fields, and streams of the old Waikiki, including Muliwai Kukaunahi, were filled. The ponds surrounding Makee Island at the edge of Kapiolani Park became a mire of mud and weeds. The Territory built a fairground on the inland side of the new canal, where rodeos brought cowboys, bucking horses, and rangy cattle to the growing town, and fireworks blazed across the night skies. The Waikiki of mansions and estates gave way to more subdivisions, although even as late as 1929, several striking residences still lined the ocean side of Kalakaua Avenue near Kapiolani Park. 1934

Ecological Importance: Act as a giant sponge: The salt marsh absorbs large volumes of water, thus minimizing the impacts of flooding and erosion and recharging groundwater. Salt marsh plants help purify water by absorbing toxins and in some cases metabolizing them into harmless substances. Most productive food factories on earth.

Of the original 215 million acres of wetlands in the U. S Of the original 215 million acres of wetlands in the U.S. (excluding Alaska and Hawaii) , about 106 million acres remain. distribution of wetlands in the U.S. in the 1780s distribution of wetlands in the U.S. in the 1900s

Current distribution of wetlands and deepwater habitats

Major Causes of Wetlands Loss and Degradation Human Actions Drainage Dredging and stream channelization Deposition of fill material Diking and damming Tilling for crop production Levees Logging Mining Construction Runoff Air and water pollutants Changing nutrient levels Releasing toxic chemicals Introducing non-native species to the ecosystem Grazing by domestic animals

Natural Threats Erosion Subsidence Sea level rise Droughts Hurricanes and other storms

Seagrass beds

Seagrass- true vascular plants Classification Five kingdom system: Monera Protista Fungi Plantae Animalia Angiosperms Gymnosperms

Seagrasses True marine angiosperm Evolved from shoreline Lillie-like plants~100 mya Vascular plants reinvaded the seas 3 different times (algae is nonvascular; i.e., no need for roots to transport water and nutrients) Can grow and reproduce while completely submerged under water Distribution: 12 genera of seagrasses (5 in the high latitude and 7 in the low latitude)

Halophila hawaiiana- only form of seagrass in Hawaii

Development of Seagrass Beds Develop in: intertidal and shallow subtidal areas on sands and muds marine inlets and bays lagoons and channels, which are sheltered from significant wave action

Ecological roles: Help stabilize the sediment Prevents resuspension of sediments in water (water is clearer) Binds substratum, reduces turbidity, and reduces erosion Sediment accumulation slows velocity of incoming water Food for many organisms Refuge for many organisms

Threats to Seagrass Beds Seagrass productivity is highly dependent on a number of factors: salinity water temperature turbidity This ecosystem is particularly sensitive to degradation due to: agricultural pollution-run-off of herbicides industrial pollution domestic pollution

Coral Reef Communities

Hermatypic corals: possess zooxanthellae are reef builders Light: Clear water Warm temperature: 18-32oC Low nutrients Low productivity in water Ahermatypic corals: no zooxanthellae rely on tentacular feeding can live in aphotic zone

Hawaiian Coral Zonation 0 m High light levels Moderate wave energy 6 m Cauliflower coral (Pocillopora meaandrina) Moderate light levels Occasional storm wave energy Lobe coral (Porites lobata) 13 m Low light levels Low wave energy Finger coral (Porites compressa) 25 m Very low light, Primarily downwelling No wave energy Plate coral (Porites rus)