Phytoplankton composition in the subtropical coastal shelf environment of Cape Canaveral, Florida

2020 ◽  
Vol 96 (4) ◽  
pp. 593-616
Author(s):  
Mary C Tate ◽  
Edward J Phlips ◽  
Ben Stelling ◽  
Susan Badylak ◽  
Leslie Landauer ◽  
...  
Keyword(s):  
Sediment Surface ◽  
Nutrient Concentrations ◽  
Strong Increase ◽  
Nutrient Loads ◽  
Column Temperature ◽  
Surface Samples ◽  
Numerical Abundance ◽  
Bottom Waters ◽  
Negative Buoyancy ◽  
Regional Land

The abundance and composition of the phytoplankton community off the coast of Cape Canaveral, Florida was examined from Fall 2013 to Summer 2015. The region is a shallow shelf environment. Water samples were collected quarterly at 24 sites from the surface and bottom of the water column; temperature and nutrient concentrations were determined. Photoautotrophic picoplanktonic prokaryotes (PPP) were consistently important in terms of numerical abundance and biomass throughout the study. Among the cyanobacteria, a surface bloom of the nitrogen-fixing filamentous species Trichodesmium was observed in Fall 2013. Dinoflagellates and diatoms were also major contributors to phytoplankton biomass. Many of the dominant dinoflagellates were mixotrophic or heterotrophic species. Nanoplanktonic eukaryotic algae were also periodically an important group in terms of biomass, such as prasinophytes (Chlorophyta). No consistent and reoccurring spatial patterns were observed, likely due to the dynamic water circulation in the open Cape Canaveral shelf environment. Depth-related differences in biomass were observed for dinoflagellates and diatoms. Dinoflagellate biomass was on average higher in surface samples, related to their motility. Conversely, diatom biomass was on average higher in bottom waters, reflecting the negative buoyancy of most species and the potential for re-suspension of cells from the sediment surface. The strong increase in the importance of PPP biomass observed in year 2 of the study may reflect the influence of high rainfall resulting from El Niño conditions on nutrient loads from regional land masses, as indicated by increases in phosphorus concentrations.

scholarly journals East Siberian Sea, an arctic region of very high biogeochemical activity

2011 ◽  
Vol 8 (1) ◽  
pp. 1137-1167 ◽  
Author(s):  
L. G. Anderson ◽  
G. Björk ◽  
S. Jutterström ◽  
I. Pipko ◽  
N. Shakhova ◽  
...  
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Surface Waters ◽  
River Runoff ◽  
Sediment Surface ◽  
Nutrient Concentrations ◽  
Terrestrial Organic Matter ◽  
East Siberian Sea ◽  
Bottom Waters ◽  
Very High

Abstract. Shelf seas are among the most active biogeochemical marine environments and the East Siberian Sea is a prime example. This sea is supplied by seawater from both the Atlantic and Pacific Oceans and has a substantial input of river runoff. All of these waters contribute chemical constituents, dissolved and particulate, but of different signatures. Sea ice formation during the winter season and melting in the summer has a major impact on physical as well as biochemical conditions. The internal circulation and water mass distribution is significantly influenced by the atmospheric pressure field. The western region is dominated by input of river runoff from the Laptev Sea and an extensive input of terrestrial organic matter. The microbial decay of this organic matter produces carbon dioxide (CO2) over-saturating all waters from the surface to the bottom relative to atmospheric values, even if the nutrient concentrations of the surface waters showed recent primary production. The eastern surface waters were under-saturated with respect to CO2 illustrating the dominance of marine primary production. The drawdown of dissolved inorganic carbon equals a primary production of ∼1 mol C m−2, which when multiplied by half the area of the East Siberian Sea, 500 000 km2, results in an annual primary production of 0.5×1012 mol C or 6×1012 gC. Even though microbial decay occurs through much of the water column it dominates at the sediment surface where the majority of organic matter ends up, and most of the decay products are added to the bottom water. High nutrient concentrations and fugacity of CO2 and low oxygen and pH were observed in the bottom waters. Another signature of organic matter decomposition, methane (CH4), was observed in very high but variable concentrations. This is due to its seabed sources of glacial origin or modern production from ancient organic matter, becoming available due to sub-sea permafrost thaw and formation of so-called taliks (layers of thawed sediments within the permafrost body). Riverine transport as well as leakage of groundwater rich in methane from decay in fresh water systems could add to the CH4 shelf water inventory as minor sources. The decay of organic matter to CO2 as well as oxidation of CH4 to CO2 contribute to a natural ocean acidification making the saturation state of calcium carbonate low, resulting in under-saturation of all the bottom waters with respect to aragonite and large areas of under-saturation down to 50% with respect to calcite. Hence, conditions for calcifying organisms are very unfavorable.

Experimental manipulations of the biomass of introduced carp (Cyprinus carpio) in billabongs. II. Impacts on benthic properties and processes1

1997 ◽  
Vol 48 (5) ◽  
pp. 445 ◽  
Author(s):  
A. I. Robertson ◽  
M. R. Healey ◽  
A. J. King
Keyword(s):  
Algal Biomass ◽  
Solid Phase ◽  
Negative Impact ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Sediment Surface ◽  
Nutrient Concentrations ◽  
Nutrient Ratios ◽  
Biofilm Development ◽  
The Impact

Two billabongs on the floodplain of the Murrumbidgee River, Australia, were partitioned in half with impermeable plastic barriers and the biomass of carp was manipulated to establish high- and low-carp biomass treatments in each billabong. Measurements of benthic variables (rates of particle settlement, biofilm development, sediment respiration, macrophyte detritus decomposition, sediment solid-phase nutrient concentrations and benthic algal biomass) were performed over four months from summer to winter 1995. Rates of particle settlement were greater in the high-carp treatment of each billabong throughout the experiment. High carp biomass had a negative impact on the autotrophic component of the biofilm developing on wood blocks placed at different heights above the sediment surface but the mechanism responsible differed between billabongs. Sediment oxygen demand became greater in the presence of a higher biomass of carp during the experiment but time courses differed between billabongs. Manipulations of carp biomass did not influence algal biomass on the sediment surface, the rate of decomposition of macrophyte detritus or sediment solid-phase nutrients or nutrient ratios. The impact of carp on benthic and surficial processes was significant but the mechanisms of change differed between billabongs.

Modelling nitrogen transport across compartments over northern Europe

2021 ◽  
Author(s):  
Stefan Hagemann ◽  
Ute Daewel ◽  
Volker Matthias ◽  
Tobias Stacke
Keyword(s):  
Baltic Sea ◽  
Land Surface ◽  
Climate Model ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Regional Climate ◽  
Marine Ecosystem ◽  
Coupled System ◽  
Nutrient Concentrations ◽  
Nutrient Loads

<p>River discharge and the associated nutrient loads are important factors that influence the functioning of the marine ecosystem. Lateral inflows from land carrying fresh, nutrient-rich water determine coastal physical conditions and nutrient concentration and, hence, dominantly influence primary production in the system. Since this forms the basis of the trophic food web, riverine nutrient concentrations impact the variability of the whole coastal ecosystem. This process becomes even more relevant in systems like the Baltic Sea, which is almost decoupled from the open ocean and land-borne nutrients play a major role for ecosystem productivity on seasonal up to decadal time scales.</p><p> </p><p>In order to represent the effects of climate or land use change on nutrient availability, a coupled system approach is required to simulate the transport of nutrients across Earth system compartments. This comprises their transport within the atmosphere, the deposition and human application at the surface, the lateral transport over the land surface into the ocean and their dynamics and transformation in the marine ecosystem. In our study, we combine these processes in a modelling chain within the GCOAST (Geesthacht Coupled cOAstal model SysTem) framework for the northern European region. This modelling chain comprises:</p><p> </p><ul><li>Simulation of emissions, atmospheric transport and deposition with the chemistry transport model CMAQ at 36 km grid resolution using atmospheric forcing from the coastDat3 data that have been generated with the regional climate model COSMO-CLM over Europe at 0.11° resolution using ERA-Interim re-analyses as boundary conditions</li> <li>Simulation of inert processes at the land surface with the global hydrology model HydroPy (former MPI-HM), i.e. considering total nitrogen without any chemical reactions</li> <li>Riverine transport with the Hydrological Discharge (HD) model at 0.0833° spatial resolution</li> <li>Simulation of the North Sea and Baltic Sea ecosystems with 3D coupled physical-biogeochemical NPZD-model ECOSMO II at about 10 km resolution</li> </ul><p> </p><p>We will present first results and their validation from this exercise.</p><p> </p>

scholarly journals Nutrient Atmospheric Deposition on Utah Lake: A Comparison of Sampling and Analytical Methods

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 123
Author(s):  
Seth Michael Barrus ◽  
Gustavious Paul Williams ◽  
A. Woodruff Miller ◽  
M. Brett Borup ◽  
LaVere B. Merritt ◽  
...  
Keyword(s):  
Atmospheric Deposition ◽  
Nutrient Loading ◽  
Inorganic Nitrogen ◽  
Dissolve Inorganic Nitrogen ◽  
Nutrient Concentrations ◽  
Nutrient Loads ◽  
Total Load ◽  
Significant Difference ◽  
Utah Lake ◽  
Collection Methods

We describe modified sampling and analysis methods to quantify nutrient atmospheric deposition (AD) and estimate Utah Lake nutrient loading. We address criticisms of previous published collection methods, specifically collection table height, screened buckets, and assumptions of AD spatial patterns. We generally follow National Atmospheric Deposition Program (NADP) recommendations but deviate to measure lake AD, which includes deposition from both local and long-range sources. The NADP guidelines are designed to eliminate local contributions to the extent possible, while lake AD loads should include local contributions. We collected side-by-side data with tables at 1 m (previous results) and 2 m (NADP guidelines) above the ground at two separate locations. We found no statistically significant difference between data collected at the different heights. Previous published work assumed AD rates would decrease rapidly from the shore. We collected data from the lake interior and show that AD rates do not significantly decline away from the shore. This demonstrates that AD loads should be estimated by using the available data and geostatistical methods even if all data are from shoreline stations. We evaluated screening collection buckets. Standard unscreened AD samples had up to 3-fold higher nutrient concentrations than screened AD collections. It is not clear which samples best represent lake AD rates, but we recommend the use of screens and placed screens on all sample buckets for the majority of the 2020 data to exclude insects and other larger objects such as leaves. We updated AD load estimates for Utah Lake. Previous published estimates computed total AD loads of 350 and 153 tons of total phosphorous (TP) and 460 and 505 tons of dissolve inorganic nitrogen (DIN) for 2017 and 2018, respectively. Using updated collection methods, we estimated 262 and 133 tons of TP and 1052 and 482 tons of DIN for 2019 and 2020, respectively. The 2020 results used screened samplers with lower AD rates, which resulted in significantly lower totals than 2019. We present these modified methods and use data and analysis to support the updated methods and assumptions to help guide other studies of nutrient AD on lakes and reservoirs. We show that AD nutrient loads can be a significant amount of the total load and should be included in load studies.

Assessment of Phytoplankton Nutrient Limitation in Productive Waters: Application of Dilution Bioassays

1993 ◽  
Vol 50 (10) ◽  
pp. 2208-2221 ◽  
Author(s):  
Hunter J. Carrick ◽  
Claire L. Schelske ◽  
Frederick J. Aldridge ◽  
Michael F. Coveney
Keyword(s):  
Large Fraction ◽  
Nutrient Concentrations ◽  
Nutrient Loads ◽  
Nutrient Reduction ◽  
High Concentration ◽  
Phytoplankton Assemblages ◽  
Lake Apopka ◽  
P Limitation ◽  
Management Scheme ◽  
Total P

Excessive nutrient loads to aquatic systems can complicate otherwise predictable relationships between nutrient concentrations and phytoplankton biomass. We conducted six bioassays on surface phytoplankton assemblages collected from productive Lake Apopka, Florida, to measure the effect of nutrient reduction on phytoplankton growth and nutritional state. Lake water was mixed with one of three diluents to create a gradient of ambient nutrient concentrations; nitrogen (N) and phosphorus (P) limitation at each level of dilution was evaluated in a 2 × 2 factorial design. While the addition of N clearly increased the growth of phytoplankton in undiluted Lake Apopka water, the phytoplankton became more P limited with the reduction of particles (30–60% dilution). Regression of algal yields onto total P concentrations from our bottle experiments indicated that an 8 μg∙L−1 change in P leads to only a 1 μg∙L−1 change in chlorophyll yield, probably due to the high concentration of P in the lake. Because dilution influences factors in addition to ambient nutrient concentrations, results obtained with the technique must be carefully evaluated. Despite this, reduction of particles to improve water quality may, in concept, be a reasonable management scheme in lakes where a large fraction of the nutrients is particulate.

scholarly journals Effects of Load Reductions on Phosphorus Concentrations in a Baltic Estuary—Long-Term Changes, Seasonal Variation, and Management Implications

2020 ◽  
Vol 44 (1) ◽  
pp. 30-43
Author(s):  
Jakob Walve ◽  
Maria Sandberg ◽  
Ragnar Elmgren ◽  
Christer Lännergren ◽  
Ulf Larsson
Keyword(s):  
Surface Water ◽  
Spring Bloom ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Nutrient Loads ◽  
P Concentration ◽  
Source Contributions ◽  
A Minor ◽  
Autumn And Winter

AbstractNutrient concentrations in coastal waters are influenced not only by land runoff, point sources, and water exchange with the sea but are also modified by settlement to and release from sediments. This complicates evaluation of measures to reduce nutrient loads. We used a mass-balance box model to calculate long-term (1968–2015) and seasonal source contributions to phosphorus (P) concentrations and cycling in the stratified Stockholm inner archipelago (IA), Baltic Sea. A drastic reduction of sewage P loads in the early 1970s reduced sewage from the major to a minor P source. Further P load reductions in the 1990s cut the direct contribution from the sewage point sources to the annual mean surface water P concentration from 10 μg l−1 (25%) to < 4 μg l−1 (12%). The largest contributions to the surface water P concentration are now (from 1996) inflowing seawater (37%), freshwater (25%), and P recycling from sediments below 20 m depth (26%). Variations in freshwater flushing give higher P concentrations in dry years, when dilution of P inputs from sediments and sewage is small, while in wet years, these inputs are greatly diluted. Source-partitioned phosphate uptake shows that the spring bloom is fueled mainly by P of seawater and freshwater origin, while the contribution from sewage point sources is minor. Since sediment P release is mostly recycled P from the settled spring bloom, the P inputs from seawater and freshwater are now the major drivers of the IA P cycle. Recycling of P from sediments boosts surface water P concentrations in autumn and winter, affecting management target concentrations.

scholarly journals Parameterization of biogeochemical sediment–water fluxes using in situ measurements and a diagenetic model

2016 ◽  
Vol 13 (1) ◽  
pp. 77-94 ◽  
Author(s):  
A. Laurent ◽  
K. Fennel ◽  
R. Wilson ◽  
J. Lehrter ◽  
R. Devereux
Keyword(s):  
Water Column ◽  
Bottom Water ◽  
In Situ Measurements ◽  
Nutrient Loads ◽  
Water Fluxes ◽  
Overlying Water ◽  
Louisiana Shelf ◽  
Biogeochemical Models ◽  
Bottom Waters

Abstract. Diagenetic processes are important drivers of water column biogeochemistry in coastal areas. For example, sediment oxygen consumption can be a significant contributor to oxygen depletion in hypoxic systems, and sediment–water nutrient fluxes support primary productivity in the overlying water column. Moreover, nonlinearities develop between bottom water conditions and sediment–water fluxes due to loss of oxygen-dependent processes in the sediment as oxygen becomes depleted in bottom waters. Yet, sediment–water fluxes of chemical species are often parameterized crudely in coupled physical–biogeochemical models, using simple linear parameterizations that are only poorly constrained by observations. Diagenetic models that represent sediment biogeochemistry are available, but rarely are coupled to water column biogeochemical models because they are computationally expensive. Here, we apply a method that efficiently parameterizes sediment–water fluxes of oxygen, nitrate and ammonium by combining in situ measurements, a diagenetic model and a parameter optimization method. As a proof of concept, we apply this method to the Louisiana Shelf where high primary production, stimulated by excessive nutrient loads from the Mississippi–Atchafalaya River system, promotes the development of hypoxic bottom waters in summer. The parameterized sediment–water fluxes represent nonlinear feedbacks between water column and sediment processes at low bottom water oxygen concentrations, which may persist for long periods (weeks to months) in hypoxic systems such as the Louisiana Shelf. This method can be applied to other systems and is particularly relevant for shallow coastal and estuarine waters where the interaction between sediment and water column is strong and hypoxia is prone to occur due to land-based nutrient loads.

Nutrient pollution at the lower reaches of Mediterranean coastal rivers in Israel

2000 ◽  
Vol 42 (1-2) ◽  
pp. 147-152 ◽  
Author(s):  
B. Herut ◽  
N. Kress ◽  
H. Hornung
Keyword(s):  
Inorganic Nitrogen ◽  
Agricultural Runoff ◽  
Point Sources ◽  
Industrial Wastes ◽  
Nutrient Concentrations ◽  
Contamination Level ◽  
Nutrient Load ◽  
Nutrient Loads ◽  
Discharge Data ◽  
Coastal Rivers

This study represents the first attempt to evaluate the nutrient load introduced into the coastal waters by the rivers along the Mediterranean coast of Israel. Measurements of nutrient concentrations (phosphate, ammonium, nitrate, nitrite, silicic acid) at two or three stations along the lower river reaches (11 rivers) were carried out annually from 1990 up to 1998. Combining the nutrient concentrations with the monthly riverine discharges we assessed the nutrient load. In general, most of the coastal rivers contain high nutrient contamination level, compared to the criteria adopted by NOAA (USA) for coastal river estuaries. The high degree of contamination is attributed to extreme low natural flow combined with the discharge of domestic and industrial wastes, and with agriculture runoff. In terms of nutrient concentrations, the Kishon River is the most polluted, followed by the Soreq, Poleg and Alexander Rivers. The preliminary estimate is that the coastal rivers transport between ~2000 to 6000 tons of dissolved inorganic nitrogen (DIN) and between ~250–800 tons of dissolved inorganic phosphorus (DIP) to the sea. An additional 3500 and 3000 tons of DIN and DIP, respectively, are supplied through the Kishon River. The load of the Poleg River is unknown (no discharge data) but expected to be significant based on nutrient concentration measured. The total load of the coastal rivers constitutes a major component among the other land-base point sources such as the Gush Dan outfall. Our estimate probably represents minimal values, as it does not include diffused input of agricultural runoff nor the riverine particulate and dissolved organic nutrient loads (which are unknown).

scholarly journals Flood water quality and marine sediment and nutrient loads from the Tully and Murray catchments in north Queensland, Australia

2009 ◽  
Vol 60 (11) ◽  
pp. 1123 ◽  
Author(s):  
Jim Wallace ◽  
Lachlan Stewart ◽  
Aaron Hawdon ◽  
Rex Keen ◽  
Fazlul Karim ◽  
...  
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Nutrient Concentrations ◽  
Large Contribution ◽  
Nutrient Loads ◽  
Nitrogen And Phosphorus ◽  
Annual Average ◽  
Nitrogen Loads ◽  
Flood Flows

Current estimates of sediment and nutrient loads from the Tully–Murray floodplain to the Great Barrier Reef lagoon are updated by taking explicit account of flood events. New estimates of flood discharge that include over-bank flows are combined with direct measurements of sediment and nutrient concentrations in flood waters to calculate the loads of sediment and nutrient delivered to the ocean during 13 floods that occurred between 2006 and 2008. Although absolute concentrations of sediment and nutrient were quite low, the large volume of water discharged during floods means that they make a large contribution (30–50%) to the marine load. By not accounting for flood flows correctly, previous estimates of the annual average discharge are 15% too low and annual loads of nitrogen and phosphorus are 47% and 32% too low respectively. However, because sediments may be source-limited, accounting for flood flows simply dilutes their concentration and the resulting annual average load is similar to that previously estimated. Flood waters also carry more dissolved organic nitrogen than dissolved inorganic nitrogen and this is the opposite of their concentrations in river water. Consequently, dissolved organic nitrogen loads to the ocean may be around twice those previously estimated from riverine data.

Dynamics of a cyanobacterial bloom in a hypereutrophic, stratified weir pool

2003 ◽  
Vol 54 (1) ◽  
pp. 27 ◽  
Author(s):  
P. A. Thompson ◽  
A. M. Waite ◽  
K. McMahon
Keyword(s):  
Growth Rates ◽  
Algal Blooms ◽  
Dissolved Inorganic Carbon ◽  
Cyanobacterial Bloom ◽  
Nutrient Concentrations ◽  
P Availability ◽  
The Public ◽  
Limiting Nutrient ◽  
Bottom Waters ◽  
Oxygenated Water

In summer 1997–1998, a bloom of the cyanobacteria Anabaena circinalis (Rabenhorst) and Anabaena spiroides (Klebahn) contaminated the Canning River (Perth, WA), forcing its closure to the public for swimming and fishing. We investigated the major nutrient fluctuations before, during and after the bloom. The river was persistently temperature stratified at least 1 month prior to the bloom. The surface and bottom layers of water had distinctly different nutrient concentrations, which meant that biomass and growth rates of the phytoplankton within each layer were limited by different nutrients. At the peak of the bloom, in the bottom waters growth rates were light limited and biomass was nitrogen limited, whereas in the surface waters biomass was controlled by phosphorus (P) availability and growth rates were probably limited by the lack of dissolved inorganic carbon. Another consequence of stratification was that, at the peak of the bloom (0.25 mg chlorophyll L−1), the mostly buoyant cyanobacteria could not access 83% of the P released from sediments during the summer period of anoxia. In this situation, the injection of oxygenated water, tested as a remediation measure for algal blooms, is likely to exacerbate a bloom by providing more of the limiting nutrient to the surface layer. However, aeration prior to the bloom may reduce P release from the sediments by preventing anoxia.

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