Summer Bloom

2 Summer Bloom The buoyant surface blooms of diazotrophic cyanobacteria (Nodularia spumigena. Aphanizomenon sp., Anabaena spp.) are the most impressive bloom phenomena in the Baltic Proper. Nodularia blooms are also of socioeconomic interest because they are potentially toxic (Wasmund, 2002). As diazotrophic cyanobacteria are not 

In contrast to the early 1980s, indications of cyanobacteria growth were recently 

---

Wassmann P, Ratkova T, Reigstad M (2005) The contribution of single and colonial cells of Phaeocystis pouchetii to spring and summer blooms in the northeastern North Atlantic. Harmful Algae 4 823-840... 

Yang H, McTaggart AR, Davidson AT, Burton H (1994) Measurement of acrylic acid and dimethyl sulfide in Antarctic coastal water during a summer bloom of Phae-ocystis pouchetii. the NIPR Symposium on Polar Biology, no. 7. National Institute of Polar Research, Tokyo, pp 43-52... 

O. ovata from Okinawa, Japan, produced a butanol-soluble compound which was lethal to mice (Nakajima et al. 1981) this was later confirmed by Yasumoto et al. (1987), who also detected slight haemolytic activity in the O. ovata cell extracts. On the other hand, crude methanol extracts of O. ovata from the Virgin Islands were found to be nontoxic to mice (Tindall et al. 1990). Summer blooms of O. ovata in the Italian coasts have been coimected to respiratory problems in swimmers and sunbathers, most probably through inhalation of toxic aerosols (Sansoni et al. 2003 Simoni et al. 2003, 2004) such problems could possibly arise from inhalation of a palytoxin-like substance (Paddle 2003). Finally, extracts of O. ovata from Brazil and the Mediterranean Sea contained substances exhibiting strong delayed haemolysis, inhibited by ouabain, and mouse lethality with symptoms typical of palytoxin (Graneli et al. 2002 Riobo et al. 2004 Penna et al. 2005). 

The high bioavailability of Cd in the marine environment from Terra Nova Bay was ascribed to upwelling of deep nutrient rich water nearshore (70). Cadmiun has a nutrient-like concentration gradient in the water column, lower close to the surface and increasing with depth (75). In the water column, Cd would be absorbed by the phytoplankton, during the summer bloom, thus becoming available for benthic molluscs in which the Cd is bioaccumulated. Ecological studies undertaken in the inner and outer part of Potter Cove showed that after seasonal ice retreat no phytoplankton bloom occured (35). In spite of the low planktonic production, rich benthic animal comunities are found in the area (29). 

During the summer, a diverse phytoplankton community establishes that is mainly based on regenerated nutrients. In coastal waters, additional nutrient input may give rise to strong summer blooms. Carstensen et al. (2007) identified four mechanisms of nutrient and/or biomass input in Danish estuaries ... 

---