Meroplankton
Meroplankton are a wide variety of aquatic organisms which have both planktonic and benthic stages in their life cycles. Much of the meroplankton consists of larval stages of larger organism.[1] Meroplankton can be contrasted with holoplankton, which are planktonic organisms that stay in the pelagic zone as plankton throughout their entire life cycle.[2]
After a period of time in the plankton, many meroplankton graduate to the
Not all meroplankton are larvae or juvenile stages of larger organisms. Many dinoflagellates are meroplanktonic, undergoing a seasonal cycle of encystment and dormancy in the benthic zone followed by excystment and reproduction in the pelagic zone before returning to the benthic zone once more.[4][5] There also exist meroplanktonic diatoms; these have a seasonal resting phase below the photic zone and can be found commonly amongst the benthos of lakes and coastal zones.[6]
Spatial distribution
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Meroplankton
The distribution of meroplankton is also highly seasonal. Many meroplankton have short residence times in the pelagic zone which follow seasonal reproduction patterns. The timing of meroplankton population rises can be used as a proxy to estimate the timing of seasonal reproduction of the species in question.[1]
Dispersal
Survival rate of Meroplankton is critical to successful development of adult organisms. One factor which often determines meroplankton survival is larval dispersal. Most species within the meroplankton community rely on ocean currents for dispersal. Currents play a key role in delivering larval organisms to specific settlement locations, where they are able to transition and mature into adult forms. Organisms which do not make it to the right settlement site are unlikely to complete their lifecycle.[9]
Food availability
A major factor affecting meroplankton survival is food availability. While some larval or juvenile stage organisms are
Diversity and abundance
Meroplankton diversity and abundance are affected by many factors. Seasonal and spatial variations are among some of the main causes of such variability. A study which was conducted in Dunkellin Estuary, determined that spawning times of many species are timed to maximise food availability at a particular time of year, while minimising presence of other species which exploit the same food source [12] Diversity and abundance are depth dependent qualities. Generally, shallow coastal waters contain far greater numbers of meroplankton than deep, open ocean waters. Most abundant regions occur at depths between 0 and 200 meters of the water column, where light penetration is highest. Availability of sunlight allows for proliferation of phytoplankton, which serves as one of the major food sources for meroplankton. Deep oceanic waters show significantly lower abundance than shelf regions, due to poor light penetration.[13]
Effects of pollution
Water and benthos pollution from industrial sources has been demonstrated to have varying effects on biological diversity and survival potential of meroplankton. One study conducted in the Vostok Bay region in Russia, demonstrated that even in the presence of industrial pollutants, most species of meroplankton were able to proliferate almost unaffected. The authors of this study attribute these findings to the fact that meroplankton are transported by ocean currents generally from cleaner open waters inshore. Furthermore, the same study also concluded that even in heavily polluted areas, meroplankton populations were able to reestablish if pollution was brought under control and sufficient time was allowed to pass. However, the rate of recolonization was demonstrated to be notably slow, on average taking about 10 years before the abundance and diversity of meroplankton returned to its original levels. This is in part due to the slow nature of detoxification of benthic sediments, which retain much of the heavy metal pollution.[14]
Meroplankton and climate change
A study conducted in the
See also
References
- ^ .
- ^ "Plankton". Britannica. Retrieved 2020-06-13.
- S2CID 199638114.
- S2CID 85192840.
- ISBN 978-1-86239-368-4, retrieved 2020-06-13
- ISSN 0142-7873.
- ^ 7. Castrob L., R., Meerhoffa E., Tapiab F. J. 2014. Spatial structure of the meroplankton community along a Patagonian Fjord – The Role of Changing Freshwater Inputs. Vo. 129A, pp.125-135
- ^ 10. Brubaker J., Largier J., Shanks A.L., 2003. Observations on the Distribution of Meroplankton During an Upwelling Event. Journal of Plankton Research. Vo. 25, No 6, pp: 645-667
- ^ 5. Brink L., Brubaker J., Hooff R., Largier J., Shanks A.L, 2002. Observations on the distribution of meroplankton during a downwelling event and associated intrusion of the Chesapeake Bay estuarine plume. Journal of Plankton Research. Vo. 24, No. 4, pp. 391-416
- ^ 3. Attrill M.J., Conway D.V.P., Eloire D., Highfeild J.M., Lindeque P.K., SomerfeildP.J., 2010. Seasonal dynamics of meroplankton assemblages at station L4. Journal of Plankton Research. Vol. 00, No. 0, pp.1-11
- ^ 2. Arntz W.E., Schnack-Schiel S., Thatje S., 2003. Developmental trade-offs in Subantarctic meroplankton communities and the enigma of low decapod diversity in high southern latitudes. Marine Ecology Progress Series. Vo. 260, pp. 195-207
- ^ 8. Byrne, P., 1995. Seasonal Composition of Meroplankton in the Dunkellin Estuary, Galway Bay. Biology and Environment: Proceedings of the Royal Irish Academy, Vo. 95B, No. 1, pp. 35–48
- ^ 9. Gallego R., Lavery S., Sewell M.A., 2014. Meroplankton Community of the Oceanic Ross Sea During Late Summer. Antarctic Science Antarctic Science, Vo. 26, No. 4, pp. 345–360
- ^ 6. Kulikova V. A., Omelyanenko V. A., Tarasov V. G. 2004. Effect of Pollution on the Meroplankton of Gaidamak Bight (Vostok Bay, Sea of Japan), Russian Journal of Ecology, Vo. 35, No. 2, pp. 91-97
- ^ 4. Beaugrand G., Kirby R. R., Lindley J. A., 2008. Climate-induced effects on the meroplankton and the benthic-pelagic ecology of the North Sea. American Society of Limnology and Oceanography, pp. 1805–1815
Sources
- Meroplankton (Australian Museum)