Inter-decadal Variability in Phytoplankton Community in the Middle Adriatic (Kaštela Bay) in Relation to the North Atlantic Oscillation

Abstract

Evaluation of a 45-year data set of primary production (PP), a 30-year data set of phytoplankton biomass, and a 51-year data set of species composition shows an increase of phytoplankton biomass and abundance in the period from the mid-1980s to the mid-1990s. Phytoplankton biomass showed bimodal seasonal cycles, with winter and spring maxima, which did not change over the past 30 years. Diatoms were the most abundant functional group and they prevailed during the colder part of the year while the dinoflagellate contribution to the phytoplankton community increased in the warmer period from May to August. Diatoms showed a significant negative correlation with sea surface temperature (SST), while dinoflagellates were positively correlated with SST. An increase of phytoplankton abundance, particularly dinoflagellate, in the period from the mid-1980s to the mid-1990s coincided with years characterized by a high North Atlantic Oscillation (NAO) index. Primary production and chlorophyll a concentration in the spring period were negatively correlated with the NAO winter (DJFM) index, probably caused by increased precipitation associated with a low or negative NAO index. PP in winter during the mixing period was positively related to the NAO winter index associated with higher temperatures and dry conditions which brought more clear days and increased input of solar radiation.

Changes in the Adriatic oceanographic properties induced by the Eastern Mediterranean Transient

“…The same, i.e. fast consumption of nutrients and restriction of primary production to the coast, has been found around the eastern Adriatic freshwater inputs (Marini et al, 2010;Ninčević Gladan et al, 2010;Viličić et al, 2011). By contrast, the open Adriatic water nutrient load is mostly controlled by the inflowing waters coming from the Ionian Sea (Šolić et al, 2008).…”

Footprints of climate change on Mediterranean Sea biota

“…We used the temperature records (annual SST, SST for a particular season and occasionally in situ temperature) provided by the papers when changes in marine biota were assessed from long-term observations, except in two cases (Nincevic-Gladan et al, 2010;Mazzocchi et al, 2012) that we obtained SST time series for the study period as described above.…”

Driving factors of the potentially toxic and harmful species of Prorocentrum Ehrenberg in a semi-enclosed Mediterranean lagoon (Tunisia, SW Mediterranean)

“…Sites most affected by HABs include bays, harbours, estuaries, lochs and lagoons, which geomorphology are worst impacted by the negative effects of eutrophication. As regards the northern Mediterranean, the bays of the Ebro Delta and Albufera, Valencia (Spain) (Garcés & Camp, 2012), the coastal lagoons of south-eastern France (Collos et al, 2009), Kastela Bay (Croatia) (Ninčević Gladan et al, 2009), and Izmir Bay (Turkey) (Bizsel & Bizsel, 2002), are examples of environments where conditions were found stimulating excessive phytoplankton proliferation. Although not documented as extensively as for the northern Mediterranean, serious HAB incidents have also been reported in southern countries, such as in the coastal waters and lagoons of the Nile delta in Egypt (Dorgham, 2011), the coastal lagoons of Tunisia (Armi et al, 2010;Sahraoui et al, 2012) and Algeria (Frehi et al, 2007).…”