The high productivity of seagrass implies a high demand for the macronutrients nitrogen and phosphorus. Additionally, several vulnerable species use Thailand’s seagrass beds as feeding ground, including dugongs and four species of sea turtles: leatherback turtle, hawksbill turtle, green turtle, and Olive Ridley turtle (Fig. (Source: Department of Marine and Coastal Resources (2017). The rates of primary production for a select range of seagrasses are typically within 0.4 to 1.5 g-C m−2 d−1 (Table 3) (Alongi, 1998). Note that, as a general rule, the deep limit of seagrass is at Secchi disc depth (Dennison and Kirkman 1996). One of these benefits provided by terrestrial and coastal and marine ecosystems is carbon sequestration. Seagrass meadows provide multiple benefits to adjacent coral reefs through various microhabitat functions. Extra-local benefits of seagrass meadows in supporting fisheries: Atlantic cod fisheries. The number of transects is determined by having some prior knowledge of the, Seyedeh Belin Tavakoly Sany, ... Rosli Hashim, in, Importance of Seagrass Management for Effective Mitigation of Climate Change, Water quality measurement methods for seagrass habitat, Functioning of Ecosystems at the Land–Ocean Interface, Treatise on Estuarine and Coastal Science, Duarte et al., 2000; Hemminga and Duarte, 2000, Nepf and Vivoni, 2000; Granata et al., 2001, Ackerman, 1986; Gambi et al., 1990; Hendriks et al., 2008, Verduin and Backhaus, 2000; Granata et al., 2001, Gacia et al., 1999; Gacia and Duarte, 2001; Hendriks et al., 2008, Gacia and Duarte, 2001; Gacia et al., 2002, Fonseca and Bell, 1998; Koch and Gust, 1999, Hemminga and Duarte, 2000; Heck and Orth, 2006, Koch and Gust, 1999; Ghisalberti and Nepf, 2002, Orth et al., 1984; Judge et al., 1993; Irlandi, 1994, 1996, Heck, 1977; Heck and Thoman, 1984; Edgar et al., 1994; Jenkins et al., 1997, Borg et al., 2006; Somaschini et al., 2008, den Hartog, 1970; Phillips and McRoy, 1980; Hemminga and Duarte, 2000; Green and Short, 2003, Nixon and Oviatt, 1973; Zieman and Wetzel, 1980; Dennison and Alberte, 1982; Wetzel and Penhale, 1983; Zieman and Zieman, 1989; Duarte, 1995; Nielsen et al., 2002, Day et al., 1989; Hillman et al., 1989; Czerny and Dunton, 1995, Czerny and Dunton, 1995; Tomasko and Dunton, 1995; Lirman and Cropper, 2003, Pirc, 1985; Cebrian et al., 1997; Hadjichristophorou et al., 1997; Mateo et al., 2003, Hillman et al. Seven species of seagrasses, across six genera, have been recorded in the Maldives (Milchakova, Phillips, & Ryabogina, 2005; G. Stevens, pers. Seagrass meadows are important ecosystems, very much comparable in appearance to grasslands in terrestrial ecosystems (Figure 5). Therefore, as island development continues to expand throughout the country, new seagrass habitat is likely to be found, and new species recorded. This is thought to be due to the balance between POC trapping and export, as well as the residence time of POC in a given estuary, which is an important factor regulating its degradation and remineralization. Habitat improvements on site can be backed by action programs in catchments whereby land-holders are encouraged to develop new attitudes toward land custodianship and new practices in land use. This article is a selection from the December issue of Smithsonian magazine Spain: A blade of seagrass serves as refuge, habitat or nourishment for other organisms, from microalgae to crustaceans… P. oceanica reefs play a role comparable to coral reefs in the dissipation of wave energy and the protection of the shoreline. We offer a number of analytical methods in this chapter to assist investigators in assessing nutrient and chlorophyll concentrations in and around seagrass beds. Seagrass meadows can also change the morphology of the islands as their roots systems consolidate and stabilize the lagoons, altering the flow dynamics and movements of the sand around the islands and their beaches (Daby, 2003). Recognizing these underwater ecosystems for their uniqueness, as well as for the many benefits they deliver is paramount. Attempts to eradicate or control the seagrass beds in lagoons surrounding tourist resorts. They've been used to fertilize fields, insulate houses, weave furniture, thatch roofs, make bandages, and fill mattresses and even car seats. (Heck et al., 1995; Bortolus et al., 1998), Cymodocia spp. The habitat complexity within seagrass meadows enhances the diversity and abundance of animals (Gratwicke & Speight, 2005). Our intention has been to offer simple, proven analytical techniques in an effort to establish common methods that produce comparable data for modestly equipped laboratories. Location-specific major threats to seagrass ecosystems and their impacts have been examined. The high productivity of seagrass implies a high demand for the macronutrients nitrogen and phosphorus. Ecology of Estuaries, Volume 1: Physical and Chemical Aspects. CRC Press, New York, NY, 419 pp. 1985, Peterson and Borum 1992). Seagrass meadows are recognized as one of the most productive ecosystems in the coastal zone. Because of these benefits, seagrasses are believe… An exception to this is in the deep waters of the Great Barrier Reef where seagrass grows as much as twice Secchi depth and more (R. Coles, pers. Other studies have shown that above-ground production of S. alterniflora is negatively correlated with latitude (Turner, 1976; Dame, 1989) and positively correlated with tidal range (Steever et al., 1976). Every year, at least 1.5 percent more seagrass meadows are lost. T.S. 1995). Style and format: Lila García y Clara Gómez, Fisheries are a main threat for many marine and freshwater #ecosystems But, @IUCN in collaboration with… days, 7 hours ago, #NewsRelease #RLE risk assessment of coral ecosystems for the Colombian Caribbean Not only do seagrass … The reef habitat, by itself, is heterogeneous in height due to local variations in accretion rates and the time span since accretion began (Kendrick et al., 2005), resulting in within-reef variation in abiotic factors relevant to other organisms (e.g., light incidence and wave exposure). As one of the planets most effective and efficient coastal systems for carbon sequestration, proper conservation and management of seagrass meadows is … Seagrasses are now considered flagship species due to their quick response to anthropogenic changes, which provide insights into overfishing, destructive fishing practices, pollution, and other threats. 10.3. (Czerny and Dunton, 1995; Tomasko and Dunton, 1995; Lirman and Cropper, 2003), Syringodium spp. Seagrass leaves – which typically create 2–12 m2 of additional surface per square meter of sediments (Duarte and Chiscano, 1999) – as well as the emerging portions of seagrass rhizomes are colonized by a variety of organisms, ranging from bacteria to filter-feeding hydrozoans and sponges (Duarte, 2000; Hemminga and Duarte, 2000). In Tanzania, a decline in seagrass was found to have a negative impact on the livelihoods of women who collect invertebrates, such as clams, sea snails and sea urchins, from seagrass meadows. In the presence of such gradients, this information should be used to allocate the effort required to determine seagrass abundance. obs.). They provide many ecosystem services (Gundersen et al., 2016), including reducing coastal erosion and storing large amounts of carbon. They occupy about 177 000 km2 along the coasts of all continents, except those in Antarctica, and extend from the intertidal zone down to depths in excess of 40 m (Duarte, 1991; Hemminga and Duarte, 2000). Reef-forming seagrasses include other species characterized by ligneous, persistent rhizomes, such as the tropical species Thalassodendron ciliatum that forms reefs in coastal areas of the Indian Ocean (Duarte et al., 1996). (Eds. Seagrasses evolved from terrestrial plants which recolonised the ocean 70 to 100 million years ago. Similar to coral reefs, seagrass meadows serve as a food source and habitat capable of fostering a diverse group of marine organisms. In: Hammond, L., Synnot, R.N. Despite all this, seagrass coverage is being lost globally at a rate of 1.5 % per year. Epiphytic layers on seagrass leaves may also contribute to the trapping of particles in seagrass beds by increasing both the roughness of the canopy and the boundary layer on the leaf surface (Koch et al., 2006). Thirteen seagrass species have been reported, with all but one present on both coasts (Department of Marine and Coastal Resources, 2016a). Without seagrass, most areas where they currently live would be a seascape of shifting sand and mud. It is a massive program that has resulted in measurable improvements in seagrass cover in the bay (Orth et al. This eutrophication process has led to the proliferation of seagrass beds in these areas. They demonstrated that restoring seagrass meadows also benefit people by providing nursery habitat for fish and shellfish that provide economic support through commercial and recreational fishing. The physical interaction between seagrass canopies and flows can also facilitate organismal recruitment within seagrass beds. In addition, exopolymeric substances secreted by epiphytes can bind sediment particles to seagrass leaves (Agawin and Duarte, 2002). Here, long-term monitoring along with a long-term vision for habitat improvement and conservation is strongly recommended. (Nixon and Oviatt, 1973; Zieman and Wetzel, 1980; Dennison and Alberte, 1982; Wetzel and Penhale, 1983; Zieman and Zieman, 1989; Duarte, 1995; Nielsen et al., 2002) and Thalassia spp. When comparing estimates of above- and below-ground production of mangroves and salt marshes, we see that mangroves are generally more productive than salt marshes above ground (Table 4). The name seagrass stems from the many species with long and narrow leaves, which grow by rhizome extension and often spread across large "meadows" resembling grassland; many species … Animals move between the corals and seagrass meadows depending on their need for food or protection from predators or waves. Seyedeh Belin Tavakoly Sany, ... Rosli Hashim, in World Seas: an Environmental Evaluation (Second Edition), 2019. Seagrasses are the flowering plants which grow in marine environments. Although wave attenuation is maximal when the meadow occupies a large portion of the water column (i.e., more than 50%; Fonseca and Cahalan, 1992), reduction in wave energy and orbital velocity occurs even when beds are located at 5–15 m depth and the plants occupy a small portion of the water column (Verduin and Backhaus, 2000; Granata et al., 2001). Copyright © 2020 Elsevier B.V. or its licensors or contributors. Mangroves and salt marshes. Gutiérrez, ... C. Wild, in Treatise on Estuarine and Coastal Science, 2011. For example, for a steeply sloping bed with a depth range of 2-3 m, depth intervals of 0.5 m may be suitable. A similar mechanism could also contribute to increased delivery of suspended particulate food to the seabed observed in seagrass meadows together with a concomitant increase in the growth of benthic organisms (Judge et al., 1993; Irlandi, 1996). P. oceanica is a long-lived species, with individual shoots and clones that live for decades and centuries, respectively (Duarte et al., 1994; Mateo et al., 1997), and the thick (1 cm) ligneous rhizomes are preserved in the sediments over millennia. The transect is a preferred stratified design for sampling along a gradient. When seagrass meadows are damaged stored carbon dioxide re-enters the atmosphere. For a gently sloping bed with a depth range of 30 m, 3 m depth intervals may be a useful guideline. Special cells within the seagrass, called chloroplasts, use energy from the sun to convert carbon dioxide and water into carbohydrates (or sugar) and oxygen through photosynthesis. The amount of below-ground biomass in wetlands has also been shown to alter significantly the degree of anoxia in soils – thereby affecting pH, as well as nutrient and contaminant cycling (Howes et al., 1981). Each square metre of seagrass is capable of absorbing 83 grams of carbon per year, and seagrass meadows hold around 15% of the carbon stored in the ocean. Seagrass canopies also have a dampening effect on waves. Of the 60 species of seagrass found worldwide, seven grow in Florida waters. However, seagrass can also directly intercept suspended sediment particles with their canopies. Indeed, the increase in Maldives seagrass meadows is often viewed negatively, especially by the tourism sector. In recognition of this, the historic United Nations Paris  Agreement of 2015 emphasizes the critical importance of conserving seagrasses and other Blue Carbon ecosystems. Seagrass meadows are poorly studied in Malaysia, even though this habitat is recognized as being an important nursery and breeding ground for marine species. ), Marine Biology. Other common marine species include Halodule spp. Although seagrass covers at most 0.2% of the seabed, it accounts for 10% of the ocean’s capacity to store carbon in soils, and these meadows store carbon dioxide an estimated 30 times faster than most terrestrial forests. There is little argument about the detrimental effects of excessive nutrient enrichment to shallow systems that contain seagrass meadows. CRC Press, Boca Raton, FL; Saenger, P.E., 1994. They are highly productive and host high biodiversity, including several associated faunal groups (Baden & Boström, 2000). Dugongs are especially sensitive to the degradation of seagrass meadows and there are only about 200 individuals left scattered along the Andaman coast and about 50 individuals in the Gulf of Thailand (Adulyanukosol & Poovachiranon, 2006). Carbon uptake and photosynthesis in a seagrass meadow. It would seem that two species, Cymodocea rotundata in Port Dickson and Cymodocea serrulata in Johor, have disappeared recently, probably due to environmental pressures (Sasekumar, 2005). Along with rainforests, mangroves, and coral reefs, seagrass meadows have also managed to catch the scientific community’s attention as the effects of extreme climatic events, human activities and invasive species (among others) take their toll on these little-known ecosystems. At each depth interval, determine the seagrass abundance by assessing it at random positions along a 25 m transect parallel to the shore. If tides are significant in the area, record the time at which the different depth estimates were made, and convert all of the depth measurements to mean sea level (MSL) using the tide table. They’re ‘ecosystem engineers’, literally creating the foundations of life. Eight different families of mangroves are found in coastal regions, including Rhizophora spp., Avicennia spp., Laguncularia spp., and Bruguiera spp. In fact, wood production accounts for as much as 60% of NPP in mangroves (Alongi, 1998). While covering approximately 0.1% of the Earth's seafloor, seagrass meadows support a wide range of biodiversity (including endemic and endangered species), stabilize sediment, filter water, provide coastal protection, produce more oxygen than rainforests, and form the basis of the world’s primary fishing grounds. Estimates of above- and below-ground net primary production (NPP) of some selected species/community types of salt marsh grasses and mangroves. Table 4. As early as 1968, Odum (1968) suggested that salt marshes transport biologically available organic matter into nearshore waters where it is subsequently remineralized, thereby enhancing secondary production on the shelf. Typical ranges of standing crop biomass for marshes and mangroves are 500–2000 g-dry-wt. The shoreward origin of the transects, which run perpendicular to shore, are determined using random numbers along the known coastal extent of the seagrass meadow. Scientists have restored vast sea grass meadows off Virginia's Eastern Shore. First, seagrass beds reduce the amount of CO 2 in the atmosphere by photosynthesizing and turning CO 2 and water (H 2 O) into oxygen (O 2) and glucose (C 6 H 12 O 6). These meadows rival tropical forests and efficient crops as the most productive ecosystems on Earth (Duarte and Chiscano, 1999), and are a source of important ecosystem services to humans, such as support for biodiversity, carbon sequestration, and sediment stabilization and coastal protection (Duarte, 2000; Hemminga and Duarte, 2000; see Chapter 12.06). Seagrass meadows are often an important downstream habitat in coastal systems. 22.4. More than 95 species of benthic and infauna animals and 149 edible fish species were found within the ecosystems (Satapoomin & Poovachiranon, 1997; Sudara et al., 1992). obs.). ), Marine Biology. Likewise, seagrass meadows are endangered by erosion, oil spills, sand mining, and domestic pollution (Choo et al., 2001). However, there are a ton of reasons that show the importance of seagrass as an ecosystem: 1) A protector of the vulnerable. Carlos M. Duarte, Hugh Kirkman, in Global Seagrass Research Methods, 2001. We recommend strong use of Integrated Catchment Management programs for the long-term success of seagrass habitat improvements. (Verduin et al., 1996). Once on site, drop the weight with the buoy at the selected depth contour to mark the station and extend a 25 m sampling transect, parallel to shore, unless the slope is negligible (i.e., < 0.5 m in 25 m), in which case, the transect can be extended at a predetermined random bearing from the marker. Because they are so photosynthetically productive, seagrass can absorb huge amounts of carbon from the atmosphere. The number of transects is determined by having some prior knowledge of the seagrass meadow and its extent. 6, No. CRC Press, New York, NY, 419 pp, Ward et al., 1984; Fonseca and Kenworthy, 1987, Roman and Able, 1988; Caffrey and Kemp, 1990, 1991; Barko et al., 1991, Kirby and Gosselink, 1976; Pomeroy and Wiegert, 1981, Moran et al., 1991; Moran and Hodson, 1994; Trefry et al., 1994, Lugo and Snedaker, 1974; Robertson and Alongi, 1992, Boto and Bunt, 1981; Twilley et al., 1985; Alongi, 1996; Alongi et al., 1998; Dittmar and Lara, 2001. To determine the patterns of seagrass abundance along a gradient using a depth gradient as the example. The dampening of waves and currents by seagrass canopies leads to increased sediment deposition (Gacia et al., 1999; Gacia and Duarte, 2001; Hendriks et al., 2008) and decreased resuspension (Lopez and Garcia, 1998). Kennish, M.J., 1986. Seagrass meadows account for a significant portion of coastal productivity in many parts of the world. The transect is a preferred stratified design for sampling along a gradient.
2020 what are the benefits of seagrass meadows