scholarly journals Eutrophication Driven by Aquaculture Fish Farms Controls Phytoplankton and Dinoflagellate Cyst Abundance in the Southern Coastal Waters of Korea

2021 ◽  
Vol 9 (4) ◽  
pp. 362
Author(s):  
Yoonja Kang ◽  
Hyun-Jung Kim ◽  
Chang-Ho Moon

We examined the dynamics of dinoflagellate cyst and phytoplankton assemblages in eutrophic coastal waters of Korea, adjacent to fish and shellfish farms. Water temperature showed seasonality, whereas salinity and pH remained relatively consistent. Dissolved inorganic nutrient levels were higher in September and at the inner stations, where aquaculture fish farms are located than those in May and at the outer stations. Canonical correspondence analysis and artificial neural network analysis revealed multiple environmental factors that affect the distribution of phytoplankton and dinoflagellate cysts. Diatoms dominated in the phytoplankton assemblages, while the protoperidinioid group dominated in the dinoflagellate cyst assemblages. Cyst abundance was higher at the outer stations than at the inner stations due to transport by fast currents, and phytoplankton abundance was positively correlated with cyst abundance. An increase in diatom abundance led to an increase in heterotrophic/mixotrophic cyst abundance, indicating that excessive uneaten food and urinary waste from the fish farms caused eutrophication in the study region and fast growth of diatoms, thereby contributing to the growth of heterotrophic/mixotrophic dinoflagellates and consequently, high abundance of heterotrophic/mixotrophic dinoflagellate cysts.

1994 ◽  
Vol 160 ◽  
pp. 68-72
Author(s):  
H Nøhr-Hansen

As part of studies of the onshore hydrocarbon potential in East Greenland undertaken by the Geological Survey of Greenland (GGU), a project was initiated with the purpose of describing the dinoflagellate cyst stratigraphy of the Lower Cretaceous succession in East Greenland (72°76°N) and correlating the exposed sections throughout the region (Nøhr-Hansen, 1993). Based on the rather sporadic occurrence of macrofossils the Lower Cretaceous sediments of East Greenland was previously dated as Aptian to Albian (Spath, 1946; Maync, 1949; Donovan, 1953, 1955, 1957). Maync (1949) reported the total exposed thickness of the ‘Aptian-Albian series’ to be more than 2000 m, whereas Surlyk (1990) noted that the Lower Cretaceous shale succession reached a cumulative thickness or 1000 m. Furthermore, Donovan (1972) reported that Hauterivian and Barremian sediments were unknown in East Greenland. Dinoflagellate cysts recorded from 40 sections throughout the region have now dated the Lower Cretaceous sequence as Barremian to Albian, and correlation of sections yields a cumulative thickness of approximately 1500m (Nøhr-Hansen, 1993).


2019 ◽  
Vol 16 (15) ◽  
pp. 2997-3008 ◽  
Author(s):  
Scarlett Trimborn ◽  
Silke Thoms ◽  
Pascal Karitter ◽  
Kai Bischof

Abstract. Ecophysiological studies on Antarctic cryptophytes to assess whether climatic changes such as ocean acidification and enhanced stratification affect their growth in Antarctic coastal waters in the future are lacking so far. This is the first study that investigates the combined effects of the increasing availability of pCO2 (400 and 1000 µatm) and irradiance (20, 200 and 500 µmol photons m−2 s−1) on growth, elemental composition and photophysiology of the Antarctic cryptophyte Geminigera cryophila. Under ambient pCO2, this species was characterized by a pronounced sensitivity to increasing irradiance with complete growth inhibition at the highest light intensity. Interestingly, when grown under high pCO2 this negative light effect vanished, and it reached the highest rates of growth and particulate organic carbon production at the highest irradiance compared to the other tested experimental conditions. Our results for G. cryophila reveal beneficial effects of ocean acidification in conjunction with enhanced irradiance on growth and photosynthesis. Hence, cryptophytes such as G. cryophila may be potential winners of climate change, potentially thriving better in more stratified and acidic coastal waters and contributing in higher abundance to future phytoplankton assemblages of coastal Antarctic waters.


2003 ◽  
Vol 77 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Martin J. Head ◽  
Geoffrey Norris

Detailed investigation of the essentially complete uppermost Miocene through Lower Pleistocene sequence in Deep Sea Drilling Project (DSDP) Hole 603C, western North Atlantic, has revealed the presence of the new dinoflagellate cyst speciesLejeunecysta hatterasensis, Lejeunecysta interrupta, Corrudinium devernaliae, andPyxidinopsis vesiculata, as well as the acritarchsLeiosphaeridia rockhallensisHead new species andLeffingwellia costatanew genus and species. Independent magnetobiostratigraphic control of DSDP Hole 603C constrains the ranges of these new species.Lejeunecysta interruptan. sp. appears to range no higher than lowermost Pliocene at 5.2 Ma,Pyxidinopsis vesiculatan. sp. has a range top at about 4.5 Ma in the Lower Pliocene,Corrudinium devernaliaen. sp. has a well-defined range of 4.7–4.1 Ma within the Lower Pliocene, andLeiosphaeridia rockhallensisn. sp. has a similarly well-defined range of 4.4–3.9 Ma within the Lower Pliocene. The presence ofLeiosphaeridia rockhallensisn. sp. in the Ramsholt Member of the Coralline Crag Formation, eastern England, supports an Early Pliocene age for this member.


2014 ◽  
Vol 186 (9) ◽  
pp. 5681-5695 ◽  
Author(s):  
M. S. Achary ◽  
S. Panigrahi ◽  
K. K. Satpathy ◽  
G. Sahu ◽  
A. K. Mohanty ◽  
...  

1992 ◽  
Vol 4 (3) ◽  
pp. 267-278 ◽  
Author(s):  
Michael G. Snape

An allochthonous block of the Nordenskjöld Formation from north-west James Ross Island, Antarctic Peninsula has yielded a diverse marine palynoflora. Dinoflagellate cyst assemblages from the 185 m thick sequence are described and compared with similar microfloras previously described from Australia, Papua New Guinea and Madagascar. A mid Tithonian (Late Jurassic) age is suggested for the section. One new genus, Helbydinium gen. nov. and four new species, Helbydinium scabratum sp. nov., Leptodinium acneum sp. nov., Leptodinium posterosulcatum sp. nov. and Rhynchodiniopsis foveata sp. nov. are described.


1984 ◽  
Vol 3 (2) ◽  
pp. 73-94 ◽  
Author(s):  
William A. S. Sarjeant

Abstract. The type material of six dinoflagellate cyst species from the Late Oligocene to Middle Miocene of northwest Germany, described originally by Gerlach (1961), is reillustrated and redescribed. It is shown to include representatives of nine species. Areosphaeridium (ex: Baltisphaeridium) pectiniforme is found to be a senior synonym of Areosphaeridium multicornutum Eaton. Systematophora placacantha is considered to be a senior synonym of Cleistosphaeridium (ex: Baltisphaeridium) panniforme (Gerlach). The new combination Rhynchodiniopsis tenuitabulata (Gerlarch) is proposed. Revised diagnoses for these three species and for Leptodinium membranigerum (Gerlach), Achomosphaera triangulata (Gerlach) and Lejeunecysta hyalina (Gerlach) are proposed. The morphology of a form described here for the first time, and tentatively attributed to Phthanoperidinium, is considered perhaps to imply a separate origin for the Phthanoperidiniaceae: for that reason familial, rather than tribal, rank is preferred for that group. The stratigraphical ranges of the nine species here recognised and of two others of Gerlach’s species redescribed in earlier papers are detailed; elimination of misattributed forms means that these ranges are shorter than the published literature suggests.


2017 ◽  
Author(s):  
M. M. Amrutha ◽  
V. Sanil Kumar

Abstract. In coastal gulfs generally, predominance of wind-seas are expected. Waves measured at a location having a water depth of 15 m in the nearshore waters of Gulf of Mannar during one year period (1 May 2015 to 30 April 2016) is used to examine the predominance of wind-seas and swells through spectral characterization. The study shows that even though the location is in a gulf, the annual average value (~ 0.84 m) of the significant wave height at this area is comparable to that along the coastal waters of the Indian subcontinent, but the annual maximum value (~ 1.7 m) recorded is much less than that (3 to 5 m) observed in those regions. Also, large seasonal variations are not observed in the wave height. The waves of the study region are under the control of sea-breeze with the maximum in the late evening hours and the minimum in the early morning hours. 53 % of the surface height variance in the study area is a result of southeast and south swells and the remaining are the east and southeast wind-seas.


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