From the scientic literature:

Harmful algal blooms and climate change: Learning from the past and present to forecast the future. Mark L. Wells a,*, Vera L. Trainer b, Theodore J. Smayda c, Bengt S.O. Karlson d,Charles G. Trick e, Raphael M. Kudela f, Akira Ishikawa g, Stewart Bernard h, Angela Wulff i,
Donald M. Anderson j, William P. Cochlan k. Harmful Algae 49 (2015) 68–93. http://dx.doi.org/10.1016/j.hal.2015.07.009

A B S T R A C T
Climate change pressures will influence marine planktonic systems globally, and it is conceivable that
harmful algal blooms may increase in frequency and severity. These pressures will be manifest as
alterations in temperature, stratification, light, ocean acidification, precipitation-induced nutrient
inputs, and grazing, but absence of fundamental knowledge of the mechanisms driving harmful algal
blooms frustrates most hope of forecasting their future prevalence. Summarized here is the consensus of
a recent workshop held to address what currently is known and not known about the environmental
conditions that favor initiation and maintenance of harmful algal blooms. There is expectation that
harmful algal bloom (HAB) geographical domains should expand in some cases, as will seasonal
windows of opportunity for harmful algal blooms at higher latitudes. Nonetheless there is only basic
information to speculate upon which regions or habitats HAB species may be the most resilient or
susceptible. Moreover, current research strategies are not well suited to inform these fundamental
linkages. There is a critical absence of tenable hypotheses for how climate pressures mechanistically
affect HAB species, and the lack of uniform experimental protocols limits the quantitative crossinvestigation
comparisons essential to advancement. A HAB ‘‘best practices’’ manual would help foster
more uniform research strategies and protocols, and selection of a small target list of model HAB species
or isolates for study would greatly promote the accumulation of knowledge. Despite the need to focus on
keystone species, more studies need to address strain variability within species, their responses under
multifactorial conditions, and the retrospective analyses of long-term plankton and cyst core data;
research topics that are departures from the norm. Examples of some fundamental unknowns include
how larger and more frequent extreme weather events may break down natural biogeographic barriers,
how stratification may enhance or diminish HAB events, how trace nutrients (metals, vitamins)
influence cell toxicity, and how grazing pressures may leverage, or mitigate HAB development. There is
an absence of high quality time-series data in most regions currently experiencing HAB outbreaks, and
little if any data from regions expected to develop HAB events in the future. A subset of observer sites is
recommended to help develop stronger linkages among global, national, and regional climate change
* Corresponding author. Tel.: +1 207 581 4322. E-mail addresses: This email address is being protected from spambots. You need JavaScript enabled to view it. (M.L. Wells), This email address is being protected from spambots. You need JavaScript enabled to view it. (V.L. Trainer), This email address is being protected from spambots. You need JavaScript enabled to view it. (T.J. Smayda), This email address is being protected from spambots. You need JavaScript enabled to view it. (Bengt S.O. Karlson), This email address is being protected from spambots. You need JavaScript enabled to view it. (C.G. Trick), This email address is being protected from spambots. You need JavaScript enabled to view it. (R.M. Kudela), This email address is being protected from spambots. You need JavaScript enabled to view it. (A. Ishikawa), This email address is being protected from spambots. You need JavaScript enabled to view it. (S. Bernard), This email address is being protected from spambots. You need JavaScript enabled to view it. (A. Wulff), This email address is being protected from spambots. You need JavaScript enabled to view it. (D.M. Anderson), This email address is being protected from spambots. You need JavaScript enabled to view it. (W.P. Cochlan).

REVIEW: OCEAN CLIMATE CHANGE, PHYTOPLANKTON COMMUNITY RESPONSES, AND HARMFUL ALGAL BLOOMS: A FORMIDABLE PREDICTIVE CHALLENGE, by Gustaaf M. Hallegraeff, Institute of Marine and Antarctic Studies, and School of Plant Science, University of Tasmania, Private Bag 55, Hobart,Tasmania 7001, Australia.  J. Phycol. 46, 220–235 (2010), 2010 Phycological Society of America, DOI: 10.1111/j.1529-8817.2010.00815.x

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 Nino 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.

 

ADVISORY BULLETIN OF THE GEOHAB SSC ON UREA FERTILIZATION

The GEOHAB Scientific Steering Committee has developed an Advisory Bulletin to provide sound scientific and technical advice to decision-makers in relation to proposals to add urea to the sea in order to stimulate algal blooms and sequester carbon for commercial purposes.

Download at  www.geohab.info. IOC and SCOR communicated the Advisory Bulletin to the IMO London Convention Scientific Group on Ocean Fertilization. See also a 57-author view point paper in the Marine Pollution Bulletin: Gilbert et al., 2008. Ocean urea fertilization for carbon credits poses high ecological risks. Marine Pollution Bulletin, doi·:10.1016/j.marpolbul.2008.03.010).



Hosted by UNESCO/IOC Project Office for IODE Oostende, Belgium