Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: A global assessment.

In order to survive in a highly competitive environment, freshwater or marine algae have to develop defense strategies that result in a tremendous diversity of compounds from different metabolic pathways. Recent trends in drug research from natural sources have shown that algae are promising organisms to furnish novel biochemically active compounds. The current review describes the main substances biosynthesized by algae with potential economic impact in food science, pharmaceutical industry and public health. Emphasis is given to fatty acids, steroids, carotenoids, polysaccharides, lectins, mycosporine-like amino acids, halogenated compounds, polyketides and toxins.

Metabolites from algae with economical impact

Prediction of the impact of global climate change
on marine HABs is fraught with difficulties. However,
we can learn important lessons from the fossil
record of dinoflagellate cysts; long-term monitoring
programs, such as the Continuous Plankton Recorder
surveys; and short-term phytoplankton community
responses to El Nin˜o Southern Oscillation
(ENSO) and North Atlantic Oscillation (NAO) episodes.
Increasing temperature, enhanced surface
stratification, alteration of ocean currents, intensification
or weakening of local nutrient upwelling,
stimulation of photosynthesis by elevated CO2,
reduced calcification through ocean acidification
(‘‘the other CO2 problem’’), and heavy precipitation
and storm events causing changes in land runoff
and micronutrient availability may all produce contradictory
species- or even strain-specific responses.
Complex factor interactions exist, and simulated
ecophysiological laboratory experiments rarely allow
for sufficient acclimation and rarely take into
account physiological plasticity and genetic strain
diversity. We can expect: (i) range expansion of
warm-water species at the expense of cold-water species,
which are driven poleward; (ii) speciesspecific
changes in the abundance and seasonal
window of growth of HAB taxa; (iii) earlier timing of
peak production of some phytoplankton; and (iv)
secondary effects for marine food webs, notably
when individual zooplankton and fish grazers are differentially
impacted (‘‘match-mismatch’’) by climate
change. Some species of harmful algae (e.g., toxic
dinoflagellates benefitting from land runoff and ⁄ or
water column stratification, tropical benthic dinoflagellates
responding to increased water temperatures
and coral reef disturbance) may become more successful,
while others may diminish in areas currently
impacted. Our limited understanding of marine ecosystem
responses to multifactorial physicochemical
climate drivers as well as our poor knowledge of the
potential of marine microalgae to adapt genetically
and phenotypically to the unprecedented pace of
current climate change are emphasized. The greatest
problems for human society will be caused by being
unprepared for significant range expansions or the
increase of algal biotoxin problems in currently
poorly monitored areas, thus calling for increased
vigilance in seafood-biotoxin and HAB monitoring
programs. Changes in phytoplankton communities
provide a sensitive early warning for climate-driven
perturbations to marine ecosystems.

/pdf/ocean-climate-change-phytoplankton-community-responses-and-3vq5zutr9a.pdf

Ocean climate change, phytoplankton community responses, and harmful algal blooms: a formidable predictive challenge

http://stopptt.com/wp-content/uploads/2013/12/32bfe50e457fb45a03.pdf

Chemical use in salmon aquaculture: A review of current practices and possible environmental effects

https://www.carey.biol.vt.edu/wp-content/uploads/2013/09/Carey_2012_Water-Res.pdf

Eco-physiological adaptations that favour freshwater cyanobacteria in a changing climate

Certain marine algae produce potent toxins that impact human health through the consumption of contaminated shellfish and finfish and through water or aerosol exposure. Over the past three decades, the frequency and global distribution of toxic algal incidents appear to have increased, and human intoxications from novel algal sources have occurred. This increase is of particular concern, since it parallels recent evidence of large-scale ecologic disturbances that coincide with trends in global warming. The extent to which human activities have contributed to their increase therefore comes into question. This review summarizes the origins and health effects of marine algal toxins, as well as changes in their current global distribution, and examines possible causes for the recent increase in their occurrence.

Van Dolah Fm

Papers

Marine algal toxins: origins, health effects, and their increased occurrence.