Dynamics in a Plankton Model with Toxic Substances and Phytoplankton Harvesting

2020 ◽  
Vol 30 (02) ◽  
pp. 2050035 ◽  
Author(s):  
Hua Zhang ◽  
Ben Niu
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Initial Population ◽  
Toxic Substances ◽  
Environmental Capacity ◽  
Existence And Stability ◽  
Small Phytoplankton ◽  
Normal Form Method ◽  
Bautin Bifurcation ◽  
Plankton Model

In this paper, a phytoplankton–zooplankton model incorporating toxic substances and nonlinear phytoplankton harvesting is established. The existence and stability of the equilibrium of this model are first investigated. The occurrence of transcritical, saddle-node, Hopf and Bautin bifurcations at different equilibria is then verified. In addition, the properties of Hopf bifurcation and Bautin bifurcation are discussed by using normal form method. These results demonstrate that phytoplankton and zooplankton populations will oscillate periodically when the harvesting level is high. More interestingly, it is found that the oscillations are always unstable for small phytoplankton carrying capacity, while the dynamics have close relations with the initial population densities for a large environmental capacity. The existence of Bautin bifurcation theoretically indicates that toxic phytoplankton can cause extinction once there exist harmful algal blooms for some time. These results are numerically illustrated for the model with spatial diffusion, which shows that local phytoplankton blooms will lead to global populations extinction.

scholarly journals The challenges of a small population exposed to multiple anthropogenic stressors and a changing climate: the St. Lawrence Estuary beluga

2021 ◽  
Vol 40 ◽  
Author(s):  
Véronique Lesage
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Extinction Risk ◽  
Small Population ◽  
Ecosystem Structure ◽  
Toxic Substances ◽  
Natal Philopatry ◽  
Lawrence Estuary ◽  
Fat Reserves ◽  
St Lawrence Estuary

Until 2012, the St. Lawrence Estuary beluga population was considered stable with about 1100 individuals. An abnormally high number of calves reported dead that year triggered a population status reassessment. This review article summarizes the findings from this reassessment and various studies subsequent to it and provides an updated analysis of carcass recovery rates up to 2019. The 2013 review indicated a decreased incidence of cancer in adults, suggesting positive impacts from the regulation of toxic substances (e.g., PCBs and PAHs). However, the review also revealed that the population initiated a decline of ca. 1% per year in the early 2000s and had reached a size of ca. 900 individuals by 2012. This decline was accompanied by high inter-annual variability in calf survival and pregnancy rates and by more frequent peripartum complications among dead females. The change in population dynamics coincided with a shift in the St. Lawrence ecosystem structure and warmer environmental conditions, suggesting a link through effects on reproductive success and adult female body condition. This was supported by the continued high calf mortality after 2012 and a documented decline of fat reserves in beluga blubber from 1998 to 2016. Other factors, such as the exposure to chronic vessel noise, increasing whale-watching activities, high contaminant levels and episodic harmful algal blooms, may also be contributing to the long-term non-recovery and current decline of the population. The strong natal philopatry and complex social system of the beluga likely increase its vulnerability to extinction risk by limiting dispersal.

scholarly journals Potential Harmful Algal Blooms (HABs) in Segara Anakan Lagoon, Central Java, Indonesia

2018 ◽  
Vol 47 ◽  
pp. 04010 ◽  
Author(s):  
Rose Dewi ◽  
Muhammad Zainuri ◽  
Sutrisno Anggoro ◽  
Tjahjo Winanto ◽  
Hadi Endrawati
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Anthropogenic Activities ◽  
Harmful Effect ◽  
Nursery Ground ◽  
Toxic Substances ◽  
Anthropogenic Pressures ◽  
Central Java ◽  
Spatial Approach ◽  
Segara Anakan Lagoon

Segara Anakan Lagoon (SAL), located along side of soutern coast on western part of Central Java 108°46'–109 ° 05'E; 7 ° 34'–7 ° 48'S. SAL is necessasrily ecosistem as nursery ground. This has been becoming important research relating to primary productivity. The existance of antropogenical activities around the area, is changing inrush input into lagoon. This is going to be worried about giving influences in physical, chemistry, and biological factors of the water and causing deflation in rate value of primer productivity. Rainy and dry season's variability with important impacts on the phytoplankton community structure, abundance and dynamics. Furthermore, the number of coastal ecosystems with identified eutrophication symptoms is increasing worldwide due to the increasing anthropogenic pressures. One of 1the first symptoms of eutrophication is enhanced phytoplankton biomass. Generally, Fitoplanton is important biological indicators in the process. However, high abundance of biomass phytoplankton could give harmful effect toward lagoon, they could produce toxic substances that will be accumulated, it can be endangering .The aim of the research is to determine and calculate potential species of Harmful Algal Blooms (HABs) in SAL with spastial and temporal approach. The spatial approach is done at seven different stations of ecological characteristics SAL, with representations: natural factors and the presence of anthropogenic activities. On the temporal approach (time series) for a year, it refers to the monsoon wind pattern, which are called season (western, the transitional season 1, eastern, and the transitional season 2).The results of laboratory tests are discussed descriptively. Phytoplankton sample were taken vertically using plankton nets, meshsize 25 μm. The result showed that SAL have been found and consisted of 82 species from 5 division phytoplankton: Chrysophyta, Chlorophyta, Cyanophyta, Pyrophyta, and Euglenophyta. 20 species from 9 genus were identified potential as HABs, with four genus of them were known having toxin and endangering for human (Nitzschia, Oscillatoria, Anabaena dan Protoperidinium).Whether, five genus do not produce toxins but giving deflation Oxygen of waters with anoxia condition (Chaetoceros, Coscinodiscus, Rhizosolenia, Thalassiosira, Thalassiotrix).The highest of HABS abundance is dominated during the transitional season II. On the spatial approach, antropoegenic characteristics station contribute to the whole height of HABs. Influence of rainfall, spatially, antropogenical pressure, and hydrodinamical watres causing enhancement of HABs potency.

scholarly journals Harmful Algal in Banyuasin Coastal Waters, South Sumatera

2016 ◽  
Vol 8 (2) ◽  
pp. 232 ◽  
Author(s):  
Riris Aryawati ◽  
Dietriech Geoffrey Bengen ◽  
Tri Prartono ◽  
Hilda Zulkifli
Keyword(s):  
Food Chain ◽  
Coastal Waters ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Biology Education ◽  
Mesh Size ◽  
Toxic Substances ◽  
Water Ecosystem ◽  
Monitoring Result ◽  
Harmful Effects

<p>Phytoplankton have important as food-chain major component and primary production of marine environment. However, high abundance of phytoplankton could give harmful effects toward water ecosystem. Moreover, they could produce toxic substances that will be accumulated within their consumer. This accumulation could be dangerous for human or animals.This research were aimed to determine and calculatespecies of harmful algae in Banyuasin coastal waters. The study was conducted on April, June, August, October and December of 2013, and in February 2014, at ten stations. Phytoplankton samples were taken vertically using plankton nets. In the form of cone-shaped with a diameter of 30 cm, length 100 cm and mesh size 30 μm.The result showed that there are 35 genera of phytoplankton. That have been found and consisted of four groups; Bacillariophyceae, Dinophyceae, Cyanophyceae and Chlorophyceae. 13 species were identified as Harmful Algal (Chaetoceros, Coscinodiscus, Nitzschia, Skeletonema, Thalassiosira, Alexandrium, Ceratium, Dinophysis, Noctiluca, Protoperidinium, Prorocentrum, Anabaena dan Oscillatoria), with seven of them were known for having toxin (Nitzschia, Alexandrium, Dinophysis, Protoperidinium Prorocentrum, Anabaena and Oscillatoria). Monitoring result showed that the highest number of species of potential harmful algal blooms (HABs) occured in June and the highest abundance occured in August, especially Chaetoceros and Skeletonema.</p><p><strong>How to Cite</strong></p><p>Aryawati, R., Bengen, D. G., Prartono, T., &amp; Zulkifli, H. (2016). Harmful Algal in Banyuasin Coastal Waters, South Sumatera. <em>Biosaintifika: Journal of Biology &amp; Biology Education</em>, 8(2), 231-239.</p>

National coastal management challenges and needs

Shore & Beach ◽  
2020 ◽  
pp. 34-43
Author(s):  
Nicole Elko ◽  
Tiffany Roberts Briggs
Keyword(s):  
Coastal Management ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Local Community ◽  
Extreme Event ◽  
Technical Information ◽  
Interdisciplinary Approach ◽  
Beach Erosion ◽  
The U.S

In partnership with the U.S. Geological Survey Coastal and Marine Hazards and Resources Program (USGS CMHRP) and the U.S. Coastal Research Program (USCRP), the American Shore and Beach Preservation Association (ASBPA) has identified coastal stakeholders’ top coastal management challenges. Informed by two annual surveys, a multiple-choice online poll was conducted in 2019 to evaluate stakeholders’ most pressing problems and needs, including those they felt most ill-equipped to deal with in their day-to-day duties and which tools they most need to address these challenges. The survey also explored where users find technical information and what is missing. From these results, USGS CMHRP, USCRP, ASBPA, and other partners aim to identify research needs that will inform appropriate investments in useful science, tools, and resources to address today’s most pressing coastal challenges. The 15-question survey yielded 134 complete responses with an 80% completion rate from coastal stakeholders such as local community representatives and their industry consultants, state and federal agency representatives, and academics. Respondents from the East, Gulf, West, and Great Lakes coasts, as well as Alaska and Hawaii, were represented. Overall, the prioritized coastal management challenges identified by the survey were: Deteriorating ecosystems leading to reduced (environmental, recreational, economic, storm buffer) functionality, Increasing storminess due to climate change (i.e. more frequent and intense impacts), Coastal flooding, both Sea level rise and associated flooding (e.g. nuisance flooding, king tides), and Combined effects of rainfall and surge on urban flooding (i.e. episodic, short-term), Chronic beach erosion (i.e. high/increasing long-term erosion rates), and Coastal water quality, including harmful algal blooms (e.g. red tide, sargassum). A careful, systematic, and interdisciplinary approach should direct efforts to identify specific research needed to tackle these challenges. A notable shift in priorities from erosion to water-related challenges was recorded from respondents with organizations initially formed for beachfront management. In addition, affiliation-specific and regional responses varied, such as Floridians concern more with harmful algal blooms than any other human and ecosystem health related challenge. The most common need for additional coastal management tools and strategies related to adaptive coastal management to maintain community resilience and continuous storm barriers (dunes, structures), as the top long-term and extreme event needs, respectively. In response to questions about missing information that agencies can provide, respondents frequently mentioned up-to-date data on coastal systems and solutions to challenges as more important than additional tools.

scholarly journals Marine harmful algal blooms (HABs) in the United States: History, current status and future trends

Harmful Algae ◽  
2021 ◽  
pp. 101975
Author(s):  
Donald M. Anderson ◽  
Elizabeth Fensin ◽  
Christopher J. Gobler ◽  
Alicia E. Hoeglund ◽  
Katherine A. Hubbard ◽  
...  
Keyword(s):  
United States ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
United States History ◽  
The United States ◽  
Current Status ◽  
Future Trends ◽  
States History

scholarly journals Mitochondrial genome evolution in pelagophyte algae

2021 ◽  
Author(s):  
Shannon J Sibbald ◽  
Maggie Lawton ◽  
John M Archibald
Keyword(s):  
Mitochondrial Genome ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
23S Rrna ◽  
Mitochondrial Genomes ◽  
Trna Genes ◽  
Unique Region ◽  
Long Read ◽  
Genomic Studies ◽  
Aureoumbra Lagunensis

Abstract The Pelagophyceae are marine stramenopile algae that include Aureoumbra lagunensis and Aureococcus anophagefferens, two microbial species notorious for causing harmful algal blooms. Despite their ecological significance, relatively few genomic studies of pelagophytes have been carried out. To improve understanding of the biology and evolution of pelagophyte algae, we sequenced complete mitochondrial genomes for A. lagunensis (CCMP1510), Pelagomonas calceolata (CCMP1756) and five strains of A. anophagefferens (CCMP1707, CCMP1708, CCMP1850, CCMP1984 and CCMP3368) using Nanopore long-read sequencing. All pelagophyte mitochondrial genomes assembled into single, circular mapping contigs between 39,376 base-pairs (bp) (P. calceolata) and 55,968 bp (A. lagunensis) in size. Mitochondrial genomes for the five A. anophagefferens strains varied slightly in length (42,401 bp—42,621 bp) and were 99.4%-100.0% identical. Gene content and order was highly conserved between the A. anophagefferens and P. calceolata genomes, with the only major difference being a unique region in A. anophagefferens containing DNA adenine and cytosine methyltransferase (dam/dcm) genes that appear to be the product of lateral gene transfer from a prokaryotic or viral donor. While the A. lagunensis mitochondrial genome shares seven distinct syntenic blocks with the other pelagophyte genomes, it has a tandem repeat expansion comprising ∼40% of its length, and lacks identifiable rps19 and glycine tRNA genes. Laterally acquired self-splicing introns were also found in the 23S rRNA (rnl) gene of P. calceolata and the coxI gene of the five A. anophagefferens genomes. Overall, these data provide baseline knowledge about the genetic diversity of bloom-forming pelagophytes relative to non-bloom-forming species.

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