scholarly journals Flotsam and jetsam: a global review of the role of inputs of marine organic matter in sandy beach ecosystems

2021 ◽  
Author(s):  
Glenn A. Hyndes ◽  
Emma Berdan ◽  
Cristian Duarte ◽  
Jenifer E. Dugan ◽  
Kyle A. Emery ◽  
...  

Sandy beaches are iconic interfaces that functionally link the ocean with the land by the flow of marine organic matter. These cross-ecosystem fluxes often comprise uprooted seagrass and dislodged macroalgae that can form substantial accumulations of detritus, termed ‘wrack’, on sandy beaches. In addition, the tissue of the carcasses of marine animals that regularly wash up on beaches form a rich food source (‘carrion’) for a diversity of scavenging animals. Here, we provide a global review of how wrack and carrion provide spatial subsidies that shape the structure and functioning of sandy beach ecosystems (sandy beaches and adjacent surf zones), which typically have little in situ primary production. We also examime the spatial scaling of the influence of these processes across the broader seascape and landscape, and identify key gaps in our knowledge to guide future research directions and priorities. Globally, large quantities of detrital kelp and seagrass can flow into sandy beach ecosystems, where microbial decomposers and animals remineralise and consume the imported organic matter. The supply and retention of wrack are influenced by the oceanographic processes that transport it, the geomorphology and landscape context of the recipient beaches, and the condition, life history and morphological characteristics of the taxa that are the ultimate source of wrack. When retained in beach ecosystems, wrack often creates hotspots of microbial metabolism, secondary productivity, biodiversity, and nutrient remineralization. Nutrients are produced during wrack break-down, and these can return to coastal waters in surface flows (swash) and the aquifier discharging into the subtidal surf. Beach-cast kelp often plays a key trophic role, being an abundant and preferred food source for mobile, semi-aquatic invertebrates that channel imported algal matter to predatory invertebrates, fish, and birds. The role of beach-cast marine carrion is likely to be underestimated, as it can be consumed rapidly by highly mobile scavengers (e.g. foxes, coyotes, raptors, vultures). These consumers become important vectors in transferring marine productivity inland, thereby linking marine and terrestrial ecosystems. Whilst deposits of organic matter on sandy beach ecosystems underpin a range of ecosystem functions and services, these can be at variance with aesthetic perceptions resulting in widespread activities, such ‘beach cleaning and grooming’. This practice diminishes the energetic base of food webs, intertidal fauna, and biodiversity. Global declines in seagrass beds and kelp forests (linked to global warming) are predicted to cause substantial reductions in the amounts of marine organic matter reaching many beach ecosystems, likely causing flow-on effects on food webs and biodiversity. Similarly, future sea-level rise and stormier seas are likely to profoundly alter the physical attributes of beaches, which in turn can change the rates at which beaches retain and process the influxes of wrack and animal carcasses. Conservation of the multi-faceted ecosystem services that sandy beaches provide will increasingly need to encompass a greater societal appreciation and the safeguarding of ecological functions reliant on beach-cast organic matter on innumerable ocean shores worldwide.

Author(s):  
Ali Mahsar ◽  
Yusli Wardiatno

<p><strong>ABSTRACT</strong></p><p>Mole crab is a benthic animal that live buried in sandy beach in the intertidal area. Mole crab has  an  important  ecological  role  and  also  has  economic  value.  The  sandy  beach  in  south  of Cilacap  and  Kebumen  is  mole  crab’s  habitat.  Mole  crab  exploitation  in  these  areas  has  been increasing  for  consumption  demand.  To  determine  the  significant  role  of  the  mole  crab  in  the provision  of  nutritious  food,  it  is  necessary  to  estimate  the  potential  of  mole  crab  biomass.  This study  aims  to  determine  standing  biomass  of  the  mole  crab  in  Kebumen  and  Cilacap  sandy beaches.  The  specimen  collection  was  conducted  by  sampling  methods  every  month  in  March 2012 to February 2013 on Bocor beach, Kebumen and June 2013 to May 2014 on Bunton beach, Cilacap. The data processing was conducted by descriptive statistics methods. The results showed that standing biomass of mole crab family Hippidae, namely Emerita emeritus and Hippa adactyla, fluctuated between 102 and 508 kg on the Kebumen sandy beach, and between 1,811 and 4,671 kg on the Cilacap sandy beach. Standing biomass of E. emeritus fluctuated between 82 and 497 kg on  the  Kebumen  sandy  beach  and  between  1,462  and  3,560  kg  on  the  Cilacap  sandy  beach.Standing biomass of H. adactyla fluctuated between 2 and 133 kg on the Kebumen sandy beach, and between 234 and 1,701 kg on the Cilacap sandy beach. The difference in standing biomass in each  location  was  caused  by  the  difference  of  sampling  time  and  environment  condition  of research area. The economic value potential of the mole crab as fishery resources is discussed.</p><p>Keywords: Emerita emeritus, Hippa adactyla, Hippidae, momentarily biomass,</p><p><strong><br />ABSTRAK</strong></p><p>Undur-undur laut adalah kelompok hewan bentik yang hidup  mengubur di daerah intertidal bersusbtrat pasir. Undur-undur laut mempunyai peran ekologis penting dan juga bernilai ekonomis. Pantai  berpasir  selatan  Cilacap  dan  Kebumen  adalah  habitat  undur-undur  laut.  Penangkapan undur-undur  laut  di  kedua  wilayah  tersebut  makin  meningkat  untuk  kebutuhan  konsumsi.  Untuk mengetahui  peran  undur-undur  laut  dalam  mendukung  penyediaan  bahan  pangan  bergizi,  perlu diketahui potensi biomassa undur-undur laut. Penelitian ini bertujuan untuk mengetahui biomassa sesaat  undur-undur  laut  dan  fluktuasinya  di  pantai  berpasir  Kabupaten  Kebumen  dan  Cilacap. Pengumpulan  spesimen  undur-undur  laut  dilakukan  dengan  metode  sampling  setiap  bulan  pada Maret 2012 hingga Februari 2013 di pantai Bocor Kebumen dan pada Juni 2013 hingga Mei 2014 di  pantai  Bunton  Cilacap.  Pengolahan  data  dilakukan  dengan  metode  statistik  deskriptif.  Hasil penelitian  menunjukkan  bahwa  besaran  biomassa  sesaat  (standing  biomass)  undur-undur  laut famili Hippidae, yaitu  Emerita emeritus  dan  Hippa adactyla, berfluktuasi  antara 102 kg hingga 508 kg di pantai berpasir Kebumen, dan antara 1.811 kg hingga 4.671 kg di pantai berpasir Cilacap. Standing biomass E. emeritus berfluktuasi antara 82 kg hingga 497 kg di pantai berpasir Kebumen dan  antara  1.462  kg  hingga  3.560  kg  di  pantai  berpasir  Cilacap.  Standing  biomass  H.  adactylaberkisar antara 2 kg hingga 133 kg di pantai berpasir Kebumen, dan antara 234 kg hingga 1.701 kg di  pantai  berpasir  Cilacap.  Perbedaan  besaran  standing  biomass  di  masing-masing  lokasi dipengaruhi  oleh  perbedaan  waktu  pengumpulan  data  undur-undur  laut  dan  perbedaan  kondisi lingkungan  lokasi  penelitian.  Potensi  ekonomi  sebagai  sumber  daya  perikanan  undur -undur  laut juga dibahas dalam paper ini.</p><p>Kata kunci: Emerita emeritus, Hippa adactyla, Hippidae, biomassa sesaat</p>


2019 ◽  
Vol 36 ◽  
pp. 1-10 ◽  
Author(s):  
Leonardo Lopes Costa ◽  
Phillipe Mota Machado ◽  
Ilana Rosental Zalmon

The role of morphodynamic features such as grain size, swash climate and wave action on the macrofauna of beaches are well-known. However, few studies have investigated natural disturbances as potential drivers of temporal community variations. In southeastern Brazil, we sampled the intertidal macrofauna of two sandy beaches to test whether seasonal disturbances as the frequency of storm wave events (SWE) and rainfall have significant influence on their composition and abundance. The macrofauna assemblage differed significantly between the rainy and the dry seasons, but rainfall was not the main driver of community changes, although both beaches are in the vicinity of extensive river plumes. Actually, SWE explained most macrofauna richness overtime, with positive effects. Our results point to the importance of learning more about the effects of poorly studied disturbances on macrofaunal communities, and based on them we strongly recommend including these seasonal phenomena when monitoring sandy beaches.


Ecology ◽  
2015 ◽  
Vol 96 (12) ◽  
pp. 3257-3269 ◽  
Author(s):  
Timothy D. Jardine ◽  
Ryan Woods ◽  
Jonathan Marshall ◽  
James Fawcett ◽  
Jaye Lobegeiger ◽  
...  

2018 ◽  
Vol 69 (8) ◽  
pp. 1248 ◽  
Author(s):  
Ryan J. Baring ◽  
Rebecca E. Lester ◽  
Peter G. Fairweather

Wrack accumulates commonly in surf zones of sandy beaches and can be a semipermanent feature. Very few studies have investigated the trophic pathways associated with wrack accumulations in sandy beach surf zones, despite their potential importance to nearshore food webs. In the present study, we were specifically interested in determining the fish–wrack trophic associations in the nearshore. Macrophytes, macroinvertebrates and fish were sampled from drifting wrack at two sites with different macrophyte compositions (i.e. algae v. an algae–seagrass mix) in South Australia. The gut contents of fish were sampled, and the δ13C and δ15N stable isotope signatures of fish, macroinvertebrates and macrophytes were analysed. Using both the stable isotope and diet data, we identified that fish are feeding among wrack accumulations, but some unexplained trophic pathways suggest that fish are also likely to be foraging over multiple habitats elsewhere for food. In contrast, there was more evidence that grazing macroinvertebrates may be feeding on and around macrophytes within the accumulations, as well as using them as habitat. Thus, the present study established some baseline trophic pathways associated with wrack accumulations in sandy beach surf zones. Given the modest evidence for use of wrack as a food source, the lower trophic levels of the food webs identified remain unknown and should be an area for future research.


1997 ◽  
Vol 45 (4) ◽  
pp. 369 ◽  
Author(s):  
Patrina Birt ◽  
Leslie S. Hall ◽  
Geoffrey C. Smith

The tongues of six species of Australian megachiropterans were studied macroscopically and microscopically to observe whether there were any morphological characteristics correlating with their foraging and feeding behaviour. Tongues varied from being extensible and brush-like (with long hair-like papillae) in Syconycteris australis, to club-like (with very few types of papillae) in Nyctimene robinsoni, to long-pointed (possessing several types of surface papillae) in the Pteropus species. The morphology of the tongue of S. australis and the Pteropus species was similar to that of nectar-feeding birds, marsupials and other mammals. N. robinsoni possessed a tongue highly structured for processing the fruit on which it feeds, whilst the tongue of the S. australis and P. scapulatus was highly structured for a diet predominantly made up of nectar. Although the surface papillae were similar among P. poliocephalus, P. alecto and P. conspicillatus, the shape of the tongue varied considerably, suggesting that there may be subtle differences between individual feeding strategies. The morphology of the tongues in this study, combined with field observations, suggest that many megachiropterans are able to consume different food types when their preferred food source is unavailable. In addition, the structure of tongue and its papillae support the role of megachiropterans in both pollination and seed dispersal.


2021 ◽  
Author(s):  
Glenn A. Hyndes ◽  
Rebecca McCleod ◽  
Rocio Suarez Jimenez ◽  
Derek Richards

Abstract Invertebrate communities and ecological processes are well understood in high-energy sandy beaches, where beach-cast wrack (macrophyte detritus) often accumulates and forms hotspots of nutrient cycling as well as enhancing diversity and driving food webs. Grazing invertebrates play a key role in recycling wrack and facilitating the transfer of nutrients for spatial subsidies across this marine-terrestrial ecotone. Cobble and boulder beaches can also form a prominent feature of wave-exposed coasts and accumulate wrack, yet we know far less about the invertebrates in these beaches and their possible role for recycling wrack. Here, we determine the biomass of detrital macrophytes on, and embedded in, the boulder matrix, as well as the density and biomass of macroinvertebrates in high-energy, boulder beaches in south-eastern New Zealand. We use these data to compare densities and biomass of wrack and invertebrates with published data for sandy beaches to examine the possible importance of these understudied coastal habitats in recycling wrack and facilitating trophic subsidies. The biomass of beach-cast macroalgae exceeded 100 g DW 0.1m-2 on boulder beaches, where the kelps Durvillaea spp. and Macrocystis pyrifera were the main forms of wrack on both types of beaches. This was comparable to many other sandy beaches across the globe. However, the total biomass of invertebrates on boulder beaches in our study was higher than that reported for sandy beaches in the region and across the globe, while densities were similar or higher than those found on sandy beaches. Like sandy beaches across the globe, amphipods were abundant on boulder beaches, however, the relatively large gastropod Diloma nigerrimum was particularly dominant in this habitat. With its known high grazing rates, combined with high densities and biomass, this grazer is likely to play a disproportionately important role in the processing of beach-cast kelp and a key role in transferring nutrients back into the ocean or to adjacent terrestrial food webs.


2013 ◽  
Vol 73 (1) ◽  
pp. 19-28 ◽  
Author(s):  
TF. Maria ◽  
AM. Esteves ◽  
J. Vanaverbeke ◽  
A. Vanreusel

The role of a dominant macrobenthic polychaete, Scolelepis squamata, in the colonisation of defaunated tropical sediments by sandy-beach nematodes was investigated and compared with a previous colonisation experiment carried out on a temperate sandy beach. Experimental cylinders, equipped with lateral windows allowing infaunal colonisation, were filled with defaunated sediment containing two treatments, with and without S. squamata. These cylinders were inserted into microcosms containing sediment with indigenous meiofauna collected from the field. The treatments were incubated in the laboratory at ambient temperature and salinity for 7, 14 and 21 days. The nematode assemblages in both treatments did not differ in composition between treatments and from the natural assemblages, suggesting that all the species were equally able to colonise the experimental cores. The presence of the polychaete did not affect the development of the nematode community composition, in contrast to the results from a previous temperate-beach experiment. However, our results did not indicate whether the difference in results was caused by the different behaviour of the polychaete specimens, or by the different composition and response of the present nematode community.


2013 ◽  
Vol 61 (2) ◽  
pp. 113-128 ◽  
Author(s):  
Elena Ricevuto ◽  
Salvatrice Vizzini ◽  
Claudio Lardicci ◽  
Abilio Soares Gomes

The objective of this study was to investigate the macrobenthic community of two compartments of the Maricá-Guarapina lagoon system, along the coast of Rio de Janeiro, Brazil, in relation to its abiotic sediment factors. An additional discrimination between sites was made, wherever the macrophyte Typha domingensis was found. This vegetation supposedly represents a potentially important food source for consumers. Furthermore, the trophic pathways were analyzed functionally by means of stable isotope analysis to assess the role of organic matter sources for consumers in the study area. In conclusion, the results showed differences between abiotic features in the compartments of the lagoon system, which, although they have affected the different species' distribution, have led to a homogeneous low-diversity system. Macrozoobenthic species tend to change with increasing distance from the sea, with a slightly different distribution in the two compartments. The macrophyte T. domingensis did not exercise any great influence on the biotic distribution and was not the main food source for consumers in the lagoon system, where, instead, sedimentary organic matter and macrophyte detritus also seem to play an important role in the trophic web.


2016 ◽  
Vol 82 (13) ◽  
pp. 3868-3874 ◽  
Author(s):  
Michelle A. Maier ◽  
Kimiko Uchii ◽  
Tawnya D. Peterson ◽  
Maiko Kagami

ABSTRACTLethal parasitism of large phytoplankton by chytrids (microscopic zoosporic fungi) may play an important role in organic matter and nutrient cycling in aquatic environments by shunting carbon away from hosts and into much smaller zoospores, which are more readily consumed by zooplankton. This pathway provides a mechanism to more efficiently retain carbon within food webs and reduce export losses. However, challenges in accurate identification and quantification of chytrids have prevented a robust assessment of the relative importance of parasitism for carbon and energy flows within aquatic systems. The use of molecular techniques has greatly advanced our ability to detect small, nondescript microorganisms in aquatic environments in recent years, including chytrids. We used quantitative PCR (qPCR) to quantify the consumption of zoospores byDaphniain laboratory experiments using a culture-based comparative threshold cycle (CT) method. We successfully quantified the reduction of zoospores in water samples duringDaphniagrazing and confirmed the presence of chytrid DNA inside the daphnid gut. We demonstrate that comparativeCTqPCR is a robust and effective method to quantify zoospores and evaluate zoospore grazing by zooplankton and will aid in better understanding how chytrids contribute to organic matter cycling and trophic energy transfer within food webs.IMPORTANCEThe study of aquatic fungi is often complicated by the fact that they possess complex life cycles that include a variety of morphological forms. Studies that rely on morphological characteristics to quantify the abundances of all stages of the fungal life cycle face the challenge of correctly identifying and enumerating the nondescript zoospores. These zoospores, however, provide an important trophic link between large colonial phytoplankton and zooplankton: that is, once the carbon is liberated from phytoplankton into the parasitic zoospores, the latter are consumed by zooplankton and carbon is retained in the aquatic food web rather than exported from the system. This study provides a tool to quantify zoospores and evaluate the consumption of zoospores by zooplankton in order to further our understanding of their role in food web dynamics.


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