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Field Guide to Marine Ecology of Kenyan Coast. Item Type Book/Monograph/Conference Proceedings Publisher Wildlife Clubs of Kenya Download date 07/10/2021 07:48:33 Link to Item http://hdl.handle.net/1834/7188 lie!d guide toto oj Keltlllllt eoosteoost Wildlife Clubs ofKenya ~ EDITOR Ayuko MiyawakiMiyawaki Sponsored by KWSlNetherlands Wetlands Conservation and Training ProgramProgram MARINE ECOSYSTEM & HABITATS The drawing above shows a model of Kenyan coast: from sandy shore across a lagoon of shallow water with sea grass and coral gardenj out to the flinging reef where the waves break and the coral rises like a wall from the depths of the ocean. The beach and lagoon are in a marine park where shellsj plantsj fish and other marine life is protected. In the marine ecosystem herej there are 6 habitatsj which have their own plants and animals that adapted to the particular environment. MANGROVE SWAMP SEAGRA.SS BED The sand is bright In the strong Mangrove trees grow along sheltered Although over 90% of marine plants r. sunlight. This fine white sand is sedimentary shoresj especially in are algae /seaweeds and made of skeletons of certain bays and estuaries. These places phytoplankton)j seagrass grows on seaweeds and cora[sj ground up by are called mangrove swamps. They shallow sandy/muddy seabedsj the waves over many seasons. have spreading roots to anchor them producing as much energy through Shoreline plays many important and small finger-like roots that stick photosynthesis [ike a rainforest. By ecological and economIC roles. up through the mud and allow the trapping sedimentsj seagrasses play Sandy beaches are the primary roots to "breathe." Most produce a vital role in stabilising mobile sand nesting habitats for sea turt[esj as [ong" torpedo-shaped seeds that and protecting shores from erosion. well as popular recreational and genninate in the mudj allowing the At first g[ance j you might see [ittle tourism area. forest to expand across the shore. marine life on muddy and sandy Howeverj seashores the least stable The roots help trap soil and sediment seabeds. But many animals are and most changeable physical before it washes out to sea hidden safely in burrows and tubes in landform system on earth. They are smotheringj and killing coral reefs. the mud. Different kinds of greatly influenced by sea and weather The trapped soi[j sediment and dead invertebratesj wormsj and bottom conditions such as windj wavesj tidesj [eaves provide rich sources of food for living fish are associated with and currents. many plants and animals. The seagrass beds.. Numerous fish At first glance a beach may not look tides regularly cover the base of these species feed directly on the [eaves [ike much of a home for plants and treesj and a wide variety of anima[sj and use the seagrass beds as sheJter anima[sj but many have become including young coral reef fishj other from predators. Seagrass beds also specially adapted to live in this harsh fishj crabsj prawnsj molluscsj and provide important, nursery grounds environment. birds live in the trees' shelter. for juveniles of fish and severa[ commercially valuable prawns. ·, ORAL GARDEN Kenyan coast, where sea temperature Lagoons formed by fringing reefs are is always above 18° C, seabed is separated from the oceans by reef fringed by shallow reefs made by flats and the reef crest where the animals called corals. Corals are waves break. In the picture above, breeding and feeding grounds for the tide is out. Twice each day, the thousands of fish and invertebrate water is low, and the reef flat is I animals. There are few plankton exposed to the sun. Twice the water because of the shortage of nutrients comes up high onto the shore. The in tropical watersi however, corals plants and animals'that live between have food source within their body the tides have the benefit of living in tissue, that is, algae: tiny plants, that the sea for part of the day. For the need sunlight to photosynthesize. rest of the time, they have to cope Therefore, most of the primary with exposure to cold, heat, and production of the coral reef happens drought. At low tide the reef flat is inside the coral, rather than in calmer and dry, so you can walk on DEEPSEA phytoplankton floatmg m the sea the reef flat and see mto the tide Sunlight is able to penetrate the first water. A healthy reef has 21'16 of all pools - you will find natural 200m, and this is the region where the the marine species living among the aquariums for juvenile fish - and life majority of ocean life is found. corals - sponges, fish, crabs, and on the rocks. On the reef flat, the Below 170lll in even clearest waters, many more organisms, often living dominating plants are seaweed and the light becomes too dim for plants symbiotically. Despite the chaotic algae. They provide food for to photosynthesize. Here only existence of life on a coral reef, the grazing animals especially limpets animals grow. Strong swimmers, ecosystem is balanced. and sea urchins, and shelter for a host such as dolphins, whales and sharks, Coral reefs also play a major role in of small worms, brittle-stars, live in deep watp outside the lagoon. protecting tropical shorelines from crustaceans, shells, and sea In deep water, light attenuation takes the storms and wave action. anemones living in the crevices and in place and therefore fewer colours can However, corals only live in warm small hollows. Many of these hide be seeni temperatures there are lower clear water and grow very slowly so away by day avoid being eaten by too. Only certain plants or animals .. -., -~'-: .:-,~~"~.~.=.' -~--~--- ~----.-~----.--- .-.. .. _:~. -:-::-:=:::=';;:::==:;:::::::==::.--_~.~-:-::-:=:::=';;:::==:;:::::::==::.--_~.~-- -----"7~:=-~---....-. - ::-:-.......... .....'1'1--------_-'- .~'''''J 1 CRAB PLOVER Dromas ardeola ndoero/aina ya kiluwHuwi 2 GHOST CRAB Osypode Sp. kisagaunga/kifukulile CAAB PLOVER I Drom.1S .lrdeol..l}.lrdeol..l) J J Ndocro/.1in.:tNdocroj.1in.:t ya Kiltlwiluwi Large black-and-white wader with black mantlelj blue-grey legs and a thicklj heavy bill. bill. A harsh barking Icrow-ow uttered by flocking birds. birds. Frequents sand and mad flat. flat. Feeding mainly on crabslj which it crushes in its powerful bill. bill. A non-breeding visitor to Kenyan Coasts mainly in August - Apri I. Some present year-round. year-round. Only crab that live in the inter-tidal zone of sandy beacheslj where they construct deepjdeepl semi-permanent burrows burrows near the high-water mark. mark. By day they generally shelter in their holeslj but at night they become activelj emerging in large numbers to look look for food. In the moonlightlj their fast movements and sandy colour give the crabs a characteristic ghost-like ghost-like appearance (hence the common name). name). The eyes are large and are wrapped around the eyestalks to give maximum all-round night vision. vision. One of the nippers is enlarged and serves as a shield against aggressorslj and as a bulldozer blade in burrowing.bUTTowing. It can also produce a rasping noise used in aggression and courtship. courtship. Generally scavengerslj also feed on bivalve molluscs and will attack and eat turtle hatchlings and cannibalise cannibalise members of their own. own. SEASHORE PLANTS All shore plants are comprised of species from numerous families and of various formslj including grasseslj shrubsl j saltworts and trees. trees. They are the plants which are tolerant of monthly spring tide immersionlj thus able to exist in highly saline soilsl j and are present above the supralittoral fringe on sandy beaches. beaches. All are important in stabilising beach sand andlj in an attempt to prevent erosionlj shore plants should be planted planted not removed. removed. ~O£.O))!:'t ee Cocos tl.fjfe.!i!1 tl.fjfe.!i!1 Mnazi • • Cqconut tree is shaped to cope with strong wind: it has palm fronds instead of branches. • • One of the most useful trees in the world. • • All parts of the tree are utilised by local communities: fronds for roof thatchlj basketslj brooms and matSj stem for timber and fuel woodj nuts for drinklj oil and meatj and shells for ornamentslj spoons and bowls. VVhis ering Pine CiSuarina eq!!!?etifp/iil)eq!!i?etifp/iil) Mvin;eMvinje • • Casuarina tree is a tree with needle-like leaves. The leaf structures of this tree help the tree to prevent heavy evaporation and loss of waterlj as the seashore is mostly hot and windy. • • Often a pioneer specieslj although originally from the Western Pacific (now naturalisedl. • • Planted as windbreakslj used as fuelwoodlj as poles for construction and in wharves. LITTORAL ZONE < ~ <The dally rise and fall of sea level Is known as tides. There are two high tides and two low tides every day. ~ < Because graVitational forces made by rotation of moon and earth produce them, there are "spring tide," < S producing greater tides, and "neap tide," smaller tides, twice during a period of a month. The differences S > between spring and neap tidal ranges determine the extent of littoral (or inter-tidal) zone. The beach is made> up of different zones namely: supralittoral zone, mostly dry, wet only a few days a year; littoral fringe'l covered by sea only during spring high tides; euIittoraI zone, exposed on every tide; sublittoral fringe, exposed only during or near spring low tides; sublittoral zone, permanently submerge. < -----UTTORAL ZONE - c--- > EX treme High Water Springs > -- ~. Me a n High Water Neaps ~ -- Mean Tide Level ~ ----f-----------~- Mean Low Water Neaps ~ I '------~--------f-f-- Extreme Low Water Springs ~ -- I --...... ~ Suprallttoral Littoral fnnge Eullttoral zone Sublittoral fnnge Sublittoral 2 1 t......-t......-- ., . lJ - l::J 1 FLUTEMOUTH Fistularia commersonii mzimarilbombori 2 BLACK-SPOT SNAPPER Lut;ianus fulviflamma tembo 3 STONEFISH Synanceia verrucosa bocho/jungu 4 BLUESPOTTED RIBBON-TAIL RAY Taeniura Iymma taa/nyenga CORNET FISH, Family Fisw!.zrid.z.:' Fisw!.zrid.z.:' \, \zim.1ri/l~o",bori Fiote,~mQu~h rFisttJ/.<'V'i"i'wmme;sQTJi7~rFisttJl.<'V'i"i'wmme;sQTJi7~ I Extremely long thin-bodied fishes with an extended tubular snout and a long whip-like taiL taiL Feed by sucking in small crustaceans and fish in pipette-like fashion.