scholarly journals The Bouraké semi-enclosed lagoon (New Caledonia) – a natural laboratory to study the lifelong adaptation of a coral reef ecosystem to extreme environmental conditions

2021 ◽  
Vol 18 (18) ◽  
pp. 5117-5140
Author(s):  
Federica Maggioni ◽  
Mireille Pujo-Pay ◽  
Jérome Aucan ◽  
Carlo Cerrano ◽  
Barbara Calcinai ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Environmental Conditions ◽  
Environmental Variability ◽  
New Caledonia ◽  
High Pco2 ◽  
Adaptive Responses ◽  
Chemical Parameters ◽  
Natural Dynamics ◽  
Natural Laboratory ◽  
Reef Ecosystem

Abstract. According to current experimental evidence, coral reefs could disappear within the century if CO2 emissions remain unabated. However, recent discoveries of diverse and high cover reefs that already live under extreme conditions suggest that some corals might thrive well under hot, high-pCO2, and deoxygenated seawater. Volcanic CO2 vents, semi-enclosed lagoons, and mangrove estuaries are unique study sites where one or more ecologically relevant parameters for life in the oceans are close to or even worse than currently projected for the year 2100. Although they do not perfectly mimic future conditions, these natural laboratories offer unique opportunities to explore the mechanisms that reef species could use to keep pace with climate change. To achieve this, it is essential to characterize their environment as a whole and accurately consider all possible environmental factors that may differ from what is expected in the future, possibly altering the ecosystem response. This study focuses on the semi-enclosed lagoon of Bouraké (New Caledonia, southwest Pacific Ocean) where a healthy reef ecosystem thrives in warm, acidified, and deoxygenated water. We used a multi-scale approach to characterize the main physical-chemical parameters and mapped the benthic community composition (i.e., corals, sponges, and macroalgae). The data revealed that most physical and chemical parameters are regulated by the tide, strongly fluctuate three to four times a day, and are entirely predictable. The seawater pH and dissolved oxygen decrease during falling tide and reach extreme low values at low tide (7.2 pHT and 1.9 mg O2 L−1 at Bouraké vs. 7.9 pHT and 5.5 mg O2 L−1 at reference reefs). Dissolved oxygen, temperature, and pH fluctuate according to the tide by up to 4.91 mg O2 L−1, 6.50 ∘C, and 0.69 pHT units on a single day. Furthermore, the concentration of most of the chemical parameters was 1 to 5 times higher at the Bouraké lagoon, particularly for organic and inorganic carbon and nitrogen but also for some nutrients, notably silicates. Surprisingly, despite extreme environmental conditions and altered seawater chemical composition measured at Bouraké, our results reveal a diverse and high cover community of macroalgae, sponges, and corals accounting for 28, 11, and 66 species, respectively. Both environmental variability and nutrient imbalance might contribute to their survival under such extreme environmental conditions. We describe the natural dynamics of the Bouraké ecosystem and its relevance as a natural laboratory to investigate the benthic organism's adaptive responses to multiple extreme environmental conditions.

scholarly journals The Bouraké semi-enclosed lagoon (New Caledonia). A natural laboratory to study the life-long adaptation of a coral reef ecosystem to climate change-like conditions

2021 ◽  
Author(s):  
Federica Maggioni ◽  
Mireille Pujo-Pay ◽  
Jérome Aucan ◽  
Carlo Cerrano ◽  
Barbara Calcinai ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reefs ◽  
Dissolved Oxygen ◽  
Environmental Conditions ◽  
New Caledonia ◽  
Future Climate Change ◽  
Chemical Parameters ◽  
The Future ◽  
Natural Laboratory ◽  
Reef Ecosystem

Abstract. According to current experimental evidence, coral reefs could disappear within the century if CO2 emissions remain unabated. However, recent discoveries of diverse and high cover reefs that already thrive under extreme conditions seem to contradict these projections. Volcanic CO2 vents, semi-enclosed lagoons and mangrove estuaries are unique study sites where one or more ecologically relevant parameters for life in the oceans are close or even worse than currently projected for the year 2100. These natural analogues of future conditions hold new hope for the future of coral reefs and provide unique natural laboratories to explore how reef species could keep pace with climate change. To achieve this, it is essential to characterize their environment as a whole, and accurately consider all possible environmental factors that may differ from what is expected in the future and that may possibly alter the ecosystem response. In this study, we focus on the semi-enclosed lagoon of Bouraké (New Caledonia, SW Pacific Ocean) where a healthy reef ecosystem thrives in warm, acidified and deoxygenated water. We used a multi-scale approach to characterize the main physical-chemical parameters and mapped the benthic community composition (i.e., corals, sponges, and macroalgae). The data revealed that most physical and chemical parameters are regulated by the tide, strongly fluctuate 3 to 4 times a day, and are entirely predictable. The seawater pH and dissolved oxygen decrease during falling tide and reach extreme low values at low tide (7.2 pHT and 1.9 mg O2 L−1 at Bouraké, vs 7.9 pHT and 5.5 mg O2 L−1 at reference reefs). Dissolved oxygen, temperature, and pH fluctuates according to the tide of up to 4.91 mg O2 L−1, 6.50 °C, and 0.69 pHT units on a single day. Furthermore, the concentration of most of the chemical parameters was one- to 5-times higher at the Bouraké lagoon, particularly for organic and inorganic carbon and nitrogen, but also for some nutrients, notably silicates. Surprisingly, despite extreme environmental conditions and altered seawater chemical composition, our results reveal a diverse and high cover community of macroalgae, sponges and corals accounting for 28, 11 and 66 species, respectively. Both environmental variability and nutrient imbalance might contribute to their survival under such extreme environmental conditions. We describe the natural dynamics of the Bouraké ecosystem and its relevance as a natural laboratory to investigate the benthic organism’s adaptive responses to multiple stressors like future climate change conditions.

scholarly journals Short Communication: Density and length-weight relationship of mudskipper (Periophthalmus spp.) in the mangrove area of Kairatu Beach, Maluku, Indonesia

2020 ◽  
Vol 21 (11) ◽  
Author(s):  
Diana Taniwel ◽  
Fredy Leiwakabessy ◽  
Dominggus - Rumahlatu
Keyword(s):  
Dissolved Oxygen ◽  
Environmental Conditions ◽  
Short Communication ◽  
Sampling Technique ◽  
Sandy Beaches ◽  
Chemical Parameters ◽  
Mangrove Area ◽  
Weight Relationship ◽  
Physical Chemical ◽  
Relationship Of

Abstract. Taniwel D, Leiwakabessy F, Rumahlatu D. 2020. Short Communication: Density and length-weight relationship of mudskipper (Periophthalmus spp.) in the mangrove area of Kairatu Beach, Maluku, Indonesia. Biodiversitas 21: 5465-5473. Mudskippers (genus Periophthalmus) fish species inhabit mudflat, sandy beaches, and mangrove areas. Their daily activities are influenced by tidal rhythms. The aim of this research was to identify the species of mudskipper, their density, and length-weight relationship of more density species in the mangrove area of ​​Kairatu beach, Maluku, Indonesia. This research was conducted from July to August 2018, 3 sampling sites using purposive sampling technique. The physical-chemical parameters of environmental conditions (temperature, dissolved oxygen, salinity, and pH of water) were measured directly on location (in-situ), while the different mudskippers species present in the study sites were identified in the laboratory at the Pattimura University. Quantitative data on population density and length and weight of individuals were obtained for four Periophthalmus species. The physical-chemical parameters of environmental conditions in the three sampling stations were within the range of optimal values previously obtained for mudskipper species. The temperatures ranged from 30.01-30.05 oC, the dissolved oxygen ranged from 7.1-7.5 mg/L, the pH ranged from 7.3-7.5, and the salinity ranged from 5-7 ‰. The four mudskippers species identified in the sampling sites were (in density descending order): Periophthalmus argentilineatus (5.05 ind/m2), P. gracilis (1.5 ind/m2), P. malaccensis (0.4 ind/m2) and P. kalolo (0.3 ind/m2). The results of the regression analysis showed that there was no significant relationship between physical-chemical parameters to mudskipper density. The results of the length-weight relationship of the two most abundant species P. argentilineatus and P. gracilis a negative allometric length-weight relationship (b<3), while the P. kalolo and P. malaccensis indicated a positive allometric growth type (b>3).

Distribution, feeding behaviour, and condition of Cape horse mackerel early life stages, Trachurus capensis, under different environmental conditions in the northern Benguela upwelling ecosystem

2014 ◽  
Vol 72 (2) ◽  
pp. 543-557 ◽  
Author(s):  
S. J. Geist ◽  
A. Kunzmann ◽  
H. M. Verheye ◽  
A. Eggert ◽  
A. Schukat ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Feeding Ecology ◽  
Environmental Conditions ◽  
Early Life ◽  
Early Life History ◽  
Horse Mackerel ◽  
Larval Phase ◽  
Recruitment Success ◽  
Wide Range ◽  
Variable Recruitment

Abstract Early life history (ELH) traits are key to understand variable recruitment success and hence the stock size of marine fish. One of the currently most puzzling ecosystems in this regard is the northern part of the Benguela Current upwelling system off Namibia. Here, populations of the formerly dominant pelagic species, sardine and anchovy, failed to recover during the last three decades after a dramatic decline. In contrast, Cape horse mackerel, Trachurus capensis, maintained a constant population size. Warming of the system and shoaling of hypoxic zones together with feedback loops within an altered foodweb are discussed to be responsible for this regime shift. In this study, we address the role of larval traits for the successful performance of the T. capensis population under the present environmental conditions with the focus on feeding ecology. We investigated seasonal variations of the geographical distribution, growth rate, feeding ecology, and nutritional condition of their ELH stages and examined relationships with water temperature, dissolved oxygen concentration, and micro-zooplankton composition. T. capensis' ELH stages showed a wide spatial and seasonal distribution, a preference for higher water temperatures (18–21°C) and presence over a wide range of dissolved oxygen concentrations (0.13–6.35 ml O2 l−1). Feeding success was high and mainly different groups of Copepoda were targeted, which were strongly size selected. The high dietary importance of micro-copepods during large parts of the larval phase indicates successful exploitation of this food source, which has increased in abundance during the last decade. It also explains observed best nutritional conditions at temperatures between 18 and 21°C, since these small copepods are commonly associated with warmer temperatures. Altogether, these traits enhance the species' probability to encounter suitable environments for the survival of their ELH stages, which is likely to lead to their high recruitment success in the northern Benguela ecosystem.

scholarly journals Assessment of the Water Quality of Jatiluhur Reservoir, the Downstream of Citarum Cascade River, Using Selected Physico-Chemical Parameters

2014 ◽  
Vol 10 (1) ◽  
Author(s):  
Lieza Corsita ◽  
Arwin Arwin ◽  
Barti Setiani Muntalif ◽  
Indah Rachmatiah Salami
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Water Level ◽  
Hydrological Regime ◽  
Quality Parameters ◽  
Biological Data ◽  
Chemical Parameters ◽  
Stream Flows ◽  
Physico Chemical

Physico-chemistry and biological data were investigated  from  October 2010 until April 2011 of Jatiluhur reservoir. A total of six sampling stations were selected for this study. The discharge and hidrological data were obtained from Perum Jasa Tirta II Jatiluhur. The results showed that the hydrological regime in the reservoir Jatiluhur was affected by global phenomenon La Nina events in 2010 and early in 2011. Stream flows were determined during sampling to range from 78  to 482.5 m3/s. The water quality findings were as follows: pH (6.93-8.81), temperature (26.37-30.6°C), dissolved oxygen (0.733-5.2 mg/l), conductivity (2.45-233µmhos/cm), COD (7.36-96.9 mg/l), turbidity (4.063-65.6 NTU), total phosphate (0.002-0.324 mg/l), total nitrogen (0.99-5.96 mg/l), chlorophyl (2.237-43.37 mg/m3), visibility (30-160 cm). The eutrophication was pronounced at Jatiluhur reservoir. Canonical Correspendence Analysis found that some water quality parameters correlated positively with the discharge and the water level.

scholarly journals Spatio-temporal patterns of the oceanic conditions and nearshore marine community in the Mid-Atlantic Bight (New Jersey, USA)

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7927 ◽  
Author(s):  
Juan C. Levesque
Keyword(s):  
New Jersey ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Environmental Conditions ◽  
Clupea Harengus ◽  
Sediment Type ◽  
Temperature Preference ◽  
Marine Fauna ◽  
The World ◽  
Marine Community

Oceanic environmental conditions influence, shape, and control the geographical range, spatial distribution, abundance, and size composition of marine fauna. Water temperature, salinity, dissolved oxygen, depth, and sediment type influence select fish life-history characteristics and community structure. Marine communities are vulnerable to major changes in environmental conditions, but the response and severity depends on various biological or ecological factors, such as resilience to stress or adaptation. Researchers around the world have predicted and documented numerous alterations in fish communities caused by ongoing significant physicochemical shifts associated with natural and potentially unnatural sources, but published studies describing the historical conditions are lacking for most regions around the world, including the coastal waters off New Jersey. Given the need to understand these processes, a multifaceted investigation was undertaken to describe, evaluate, and compare the oceanic conditions and nearshore marine fauna community off New Jersey during 1988 through 2015. Findings showed the oceanic conditions varied over time and space. Mean surface water temperature increased significantly about 0.6 °C per decade, mean salinity decreased about 1.3 psu per decade, and dissolved oxygen increased 0.09 mg/l per decade. Over 20.4 million fish and invertebrates (1,338.3 mt) representing 214 (water temperature preference classified) species (not including unidentified species) were collected within 15 strata (areas: 12−26) off the coast of New Jersey from 1988 to 2015. Three marine fauna water temperature preference groups (coldwater-adapted, warmwater-adapted, and subtropic-adapted) were identified in the study area. The main coldwater-adapted species collected were longfin squid (Loligo pealei) (n = 2, 225, 975), Atlantic herring (Clupea harengus) (n = 544, 032), and little skate (Leucoraja erinacea) (n = 316, 356), while Atlantic butterfish (Peprilus triacanthus) (n = 2, 873, 138), scup (Stenotomus chrysops) (n = 1, 318, 569), and northern searobin (Prionotus carolinus) (n = 503, 230) represented the warmwater-adapted group. Bay anchovy (Anchoa mitchilli) (n = 9, 227, 960), striped anchovy (Anchoa hepsetus) (n = 245, 214), and Atlantic moonfish (Vomer setapinnis) (n = 38, 691) denoted the subtropic-adapted group. Subtropic-adapted species were the most abundant and coldwater-adapted were the least abundant water temperature preference group. The estimated abundance of coldwater-adapted species declined, warmwater-adapted species slightly increased, and subtropic-adapted species decreased with time, which suggest the environmental conditions are influencing and thereby shifting the marine community.

scholarly journals Physico-chemical Parameters of Koshi River at Kushaha Area of Koshi Tappu Wildlife Reserve

Our Nature ◽  
1970 ◽  
Vol 9 (1) ◽  
pp. 156-167 ◽  
Author(s):  
D. Thapa Chhetry ◽  
J. Pal
Keyword(s):  
Dissolved Oxygen ◽  
Water Temperature ◽  
Air Temperature ◽  
Oxygen Demand ◽  
Summer Season ◽  
Biological Oxygen Demand ◽  
Total Alkalinity ◽  
Total Hardness ◽  
Chemical Parameters ◽  
Wildlife Reserve

The Koshi river is the major tributaries of the Ganges which originates from the snowy peaks of Tibetan plateau in the central Himalayas. Its total catchment area is 60,400 km2, of which 28,140 km2 lies in Nepal, while the remainder is situated in Tibet. It passes from Nepal to India via the Koshi Tappu Wildlife Reserve area of Nepal. It destroys large area through floods, especially in India. This paper deals with the air temperature and phyco-chemical parameters like temperature, transparency, pH, oxygen, carbondioxide, alkalinity, hardness, chloride and biological oxygen demand of water of Koshi river at Kushaha area of Koshi Tappu Wildlife Reserve. The water temperature was recorded maximum in summer season but the transparency, pH, dissolved oxygen, total alkalinity and total hardness were recorded maximum in winter season. Similarly, free carbondioxide was maximum in rainy season and chloride and biological oxygen demand were recorded maximum in summer season. The air temperature and water temperature had positive and significant correlation with free carbondioxide and biological oxygen demand. Dissolved oxygen had positive and significant correlation with pH, total alkalinity and total hardness. Similarly, total alkalinity had positive and significant correlation with transparency, total hardness, chloride etc.DOI: http://dx.doi.org/10.3126/on.v9i1.5746

scholarly journals Dynamic variation of supernatant quality in a dairy shed waste stabilisation pond system

2007 ◽  
Vol 55 (11) ◽  
pp. 245-255 ◽  
Author(s):  
J. Fyfe ◽  
M. Sivakumar ◽  
D. Hagare ◽  
A. Jenkins
Keyword(s):  
Dissolved Oxygen ◽  
Vertical Mixing ◽  
Monitoring Program ◽  
Spatial And Temporal Variation ◽  
Chemical Parameters ◽  
Two Stage ◽  
Spatial Homogeneity ◽  
Pond System ◽  
Oxidation Reduction ◽  
External Stimuli

An intensive monitoring program of a standard two-stage dairy shed waste stabilisation pond system was undertaken to determine the incidence and extent of spatial and temporal variation of basic physio-chemical parameters, and to shed light on the longer term dynamic nature of in-pond conditions. The anaerobic–facultative pond system, located in a remote rural area, treats wastewater from the hosing down and hydraulic flushing of the milking parlour and holding yard at the farm dairy shed. A number of multi-parameter water quality field monitoring probes were permanently deployed at various locations within the two ponds to enable continuous measurement of temperature, pH, conductivity and dissolved oxygen. In addition, profiling of the supernatant of both ponds was undertaken at different times of the year to examine vertical variation of the same parameters. Continuous monitoring revealed spatial homogeneity in EC and pH levels in the upper metre of both ponds. Physio-chemical parameters also appear to change uniformly across the ponds in response to external stimuli such as rainfall. Neither pond, however, exhibits homogeneity down the profile of the supernatant. Seasonal stratification is prevalent in the facultative pond suggesting poor vertical mixing, while the anaerobic pond is notably affected by sludge accumulation. A long-term pattern of rising conductivity in both ponds indicated accumulation of dissolved salt species in the system due to recirculation of reclaimed effluent for hydraulic flushing of the dairy shed. In the facultative pond, diurnal fluctuations in dissolved oxygen, oxidation-reduction potential and turbidity during warmer months of the year closely followed temperature swings. The extensive data collected in this study provides a detailed picture of the physio-chemical dynamics of two-stage stabilisation pond systems treating dairy shed wastewater.

Environmental conditions of the Suape estuarine-port complex area (Pernambuco, Brazil): phytoplankton biomass and hydrological parameters

2018 ◽  
Vol 99 (2) ◽  
pp. 291-301
Author(s):  
Isis Amália Cordeiro ◽  
Fernando Antônio Do Nascimento Feitosa ◽  
Manuel De Jesus Flores Montes ◽  
Amanda Yumi Otsuka ◽  
Alex Costa Silva
Keyword(s):  
Dissolved Oxygen ◽  
Environmental Conditions ◽  
Rainy Season ◽  
High Tide ◽  
Dry Season ◽  
Water Transparency ◽  
Industrial Complex ◽  
Productive Capacity ◽  
Chl A ◽  
Anthropogenic Action

The Suape coastal zone has suffered since the 1980s the effects of anthropogenic action due to the construction of the industrial complex of Suape. This work aimed to evaluate the environmental conditions and possible eutrophication processes of the area. Six campaigns were carried out, three in the dry season (November 2015, January and April 2016) and three in the rainy season (July 2015, July and August 2016). Water samples were collected at the surface during low tide and high tide, in neap tides. Salinity ranged from 19.75 to 37.20, the dissolved oxygen rate ranged from 61.75 to 125.90% and chlorophyll-a from 0.02 to 3.48 mg m−3. Water transparency, temperature, nitrate and silicate presented significant seasonal variation, the concentrations of nutrients being higher in the rainy season and the others in the dry season. Water transparency, salinity, dissolved oxygen saturation and chl-a <20 µm showed significant differences for tide, being higher at high tide, and at low tide for chl-a of <20 µm. The low content of dissolved inorganic nutrient salts and chl-a were indicative of an area still free of eutrophication. Anthropogenic changes in the environment have led to greater marine interference and consequently to a reduction of the productive capacity of the system.

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