Impact of the climate change on the West coast of Algeria: Gulf of Oran, Arzew and Mostaganem.

Different hydro climatic conditionsat and above a continental shelf have significant effects on the ecology of theenvironment (temperature, nutrient richness and pelagic production). Indeed,bioclimatic changes defined clearly reflects the prevailing conditions imposedabove the continental shelf. Based on contributions made to the sea (rainfall,temperature, wind ...) and those put together by the internal dynamics can bedistinguished marine years that correspond to low enrichment in terms of anychange in continental and marine conditions generally short and strongenrichment of years corresponding to eventful years and transformations ofcontinental and marine conditions, strong shifts in time. Thus, a hot or coldbut very fluctuating period influence the marine ecosystem and phytoplankton growth. Also, the impact of development on the coastal and marine environmentis localized mainly in the coastal metropolitan areas characterized by highurbanization and concentration of activities. Keywords:climate change; environmental variability; Ecosystem vulnerability; West coastof Algeria

Presence of Cyrtograpsus angulatus Dana, 1851 (Decapoda, Brachyura) on the Chilean northern Patagonian coast

The marine fauna of decapod Crustacea, in all its diversity, can be negatively affected as a result of environmental changes, both on a local or a global scale. The present study aims to report the existence of Cyrtograpsus angulatus Dana, 1851, on the northern Patagonian coast, while concurrently describing some other decapod species associated with the various habitats. C. angulatus was originally described from the Chilean coast north of 36°43S, and the present study revealed its presence down to 44°S. In the estuaries investigated, C. angulatus is the exclusive decapod species, whereas in coastal zones it can coexist with other species of marine decapods. Nevertheless, according to the null model of the co-occurrence of species, the species associations tested did not show any structured pattern. Some ecological and biogeographical patterns in relation to this species and its biocoenoses are discusse

Assessment of surface water chemistry and algale biodiversity in the Bay of Mostaganem and the Cheliff estuary: North-western Algeria

Anthropogenic activities have led to water quality deterioration in many parts of the word, especially in Northwest Algeria. The current work investigated the spatiotemporal variations of water quality in the Cheliff River, samples for physico-chemical were performed at different periods from 2004 to 2007, the results chowed that nitrate (NO3-) intake is very high especially in the month of February 2006 (26 mg/l) and February 2007 (37 mg/l), nitrite (NO2-) values also exceed the standard for samples taken at the estuary (and the sea), ie 0.96 mg/l in the month of February 2006 and 0.98 mg/l in April 2007;the Ammonium (NH4+) contributions are due to the River because the value recorded at the estuary (4.22 in February 2006) ;silicate (SiO2) varies greatly depending on the River flow resulting from soil leaching SOUR to the estuary where we see the maximum values of 20.10 mg/l in the month of February 2007 and 19.1 mg/l in March 2005. The recorded values of elements phosphorus (PO4---) are high and very variable from 0.01 to 1.90 mg/l for the River, 0.01- 0.80 mg/l for the estuary and 0- 0.49 mg/l for the sea. The analyzed biological confirmed a total of 41 phytoplankton speciesand31 macroalgae species. So, Aquatic ecosystems are particulury vulnerable to environmental change and many are, at present, severely degraded

Assessment of Surface Water Chemistry and Algale Biodiversity in the Bay of Mostaganem and the Cheliff Estuary: North-western Algeria

Anthropogenic activities have led to water quality deterioration in many parts of the word, especially in Northwest Algeria. The current work investigated the spatiotemporal variations of water quality in the Cheliff River, samples for physico-chemical were performed at different periods from 2004 to 2007, the results chowed that nitrate (NO3-) intake is very high especially in the month of February 2006 (26 mg/l) and February 2007 (37 mg/l), nitrite (NO2-) values also exceed the standard for samples taken at the estuary (and the sea), ie 0.96 mg/l in the month of February 2006 and 0.98 mg/l in April 2007;the Ammonium (NH4+) contributions are due to the River because the value recorded at the estuary (4.22 in February 2006) ;silicate (SiO2) varies greatly depending on the River flow resulting from soil leaching SOUR to the estuary where we see the maximum values of 20.10 mg/l in the month of February 2007 and 19.1 mg/l in March 2005. The recorded values of elements phosphorus (PO4---) are high and very variable from 0.01 to 1.90 mg/l for the River, 0.01- 0.80 mg/l for the estuary and 0- 0.49 mg/l for the sea. The analyzed biological confirmed a total of 41 phytoplankton speciesand31 macroalgae species. So, Aquatic ecosystems are particulury vulnerable to environmental change and many are, at present, severely degraded

Impact of the climate change on the West coast of Algeria: Gulf of Oran, Arzew and Mostaganem.

Different hydro climatic conditions at and above a continental shelf have significant effects on the ecology of the environment (temperature, nutrient richness and pelagic production). Indeed, bioclimatic changes defined clearly reflects the prevailing conditions imposed above the continental shelf. Based on contributions made to the sea (rainfall, temperature, wind ...) and those put together by the internal dynamics can be distinguished marine years that correspond to low enrichment in terms of any change in continental and marine conditions generally short and strong enrichment of years corresponding to eventful years and transformations of continental and marine conditions, strong shifts in time. Thus, a hot or cold but very fluctuating period influence the marine ecosystem and phytoplankton growth. Also, the impact of development on the coastal and marine environment is localized mainly in the coastal metropolitan areas characterized by high urbanization and concentration of activities

Physico-chemical characterization of surface waters of the west coast of Algeria: Bay of Mostaganem and Cheliff estuary

A follow-up in 2013 of the indicators of pollution (temperature, hydrogen potential, salinity, dissolved oxygen, ammonium, nitrites, nitrates, orthophosphates, ortho silicates, biological oxygen demand, chemical oxygen demand, suspended solids) in surface water was performed, in order to estimate the physicochemical quality of the west coast of Algeria. The results obtained revealed the existence of a water contamination by domestic and industrial waste water conveyed to the north by the Cheliff River for discharge into the Bay of Mostaganem, marked by significant space-time variations. In January (24 mg / l), the values of nitrates recorded west of the mouth of Cheliff exceed norms. Ammonium records strong concentrations in January (1.2 mg NH4+/ l) and in February (0.8 mg /l). Nitrites such lagging of high contents in January (NO2- 0.99 mg / l) and February (NO2- 0.59 mg /l), respectively. The ortho phosphates post a maximum concentration in January (6.6mg PO43-/ l). In addition, the organic matter rate measured in surface water is maximum during periods of flooding especially in January (7.51 mg / l) and lowest in the exceptionally dry season in August (2.19 mg / l)

Impact of the Climate Change on the West Coast of Algeria: Gulf of Oran, Arzew and Mostaganem.

Different hydro climatic conditionsat and above a continental shelf have significant effects on the ecology of theenvironment (temperature, nutrient richness and pelagic production). Indeed,bioclimatic changes defined clearly reflects the prevailing conditions imposedabove the continental shelf. Based on contributions made to the sea (rainfall,temperature, wind ...) and those put together by the internal dynamics can bedistinguished marine years that correspond to low enrichment in terms of anychange in continental and marine conditions generally short and strongenrichment of years corresponding to eventful years and transformations ofcontinental and marine conditions, strong shifts in time. Thus, a hot or coldbut very fluctuating period influence the marine ecosystem and phytoplankton growth. Also, the impact of development on the coastal and marine environmentis localized mainly in the coastal metropolitan areas characterized by highurbanization and concentration of activities

CRUSTACEAN ZOOPLANKTON COMMUNITIES IN CHILOE ISLAND COASTAL LAKES (42 degrees S, CHILE)

The lakes of Chiloe Island have a high dissolved organic carbon concentration (known as 'humic') and show a connection with brackish water. They also display a high species richness of crustacean zooplankton. The aim of the present study is to characterize the potential factors that explain crustacean species richness in Chiloe Island lakes. To that purpose parameters of the abiotic environment were determined. The results of PCA performed on those data revealed the existence of three lakes with high crustacean species richness that are relatively deep, show high nitrogen concentrations, and are located at relatively high altitude. In contrast, there are two lakes with low species richness, high mineral concentration, and situated at low altitude. One of these lowland lakes gives rise to a river effluent to the sea, and it is connected to the other lake; these observations agree with the results of a performed cluster analysis. Nevertheless, the co-occurrence null model analysis revealed the absence of regulator patterns in species associations, which could be explained to the fact that many of the species occur in most of the lakes. These results are markedly different in comparison to Patagonian lakes of Argentina and Chile that have a low crustacean species number

CALANOID COPEPODS IN CENTRAL CHILEAN AND CHILEAN PATAGONIAN LAKES (33-55 degrees S, CHILE), PROBABLE ECOLOGICAL KEY ROLE IN PELAGIC ENVIRONMENTS

The Patagonian lakes (38-55 degrees S) are characterized by their marked oligotrophy, low number of species of crustacean zooplankton, and a marked predominance of calanoid copepods. Within this context, we considered that a review about the ecology of the zooplankton in central and southern Chilean lakes would be useful, aiming to understand the ecological importance of this group. Data obtained from the literature for freshwater bodies in central and southern Chilean lakes were analysed. In addition, data from various bays with widely differing trophic status in Llanquihue Lake were examined. The results revealed the existence of originally pristine and oligotrophic sites, all with a low number of species and marked calanoid dominance. However, in northern Patagonia there are many lakes in which human intervention has caused an increase in phytoplankton activity, with a consequent replacement of calanoid copepods by daphniid cladocerans. Other important factors that could affect the zooplankton community would be fish predation, which is due to generate a decrease in large-bodied groups of zooplankton; and stress due to exposure to natural ultraviolet radiation. Ecological, biogeographical, and evolutionary topics are discussed within the framework described

PRESENCE OF CYRTOGRAPSUS ANGULATUS DANA, 1851 (DECAPODA, BRACHYURA) ON THE CHILEAN NORTHERN PATAGONIAN COAST

The marine fauna of decapod Crustacea, in all its diversity, can be negatively affected as a result of environmental changes, both on a local or a global scale. The present study aims to report the existence of Cyrtograpsus angulatus Dana, 1851, on the northern Patagonian coast, while concurrently describing some other decapod species associated with the various habitats. C. angulatus was originally described from the Chilean coast north of 36 degrees 43'S, and the present study revealed its presence down to 44 degrees S. In the estuaries investigated, C. angulatus is the exclusive decapod species, whereas in coastal zones it can coexist with other species of marine decapods. Nevertheless, according to the null model of the co-occurrence of species, the species associations tested did not show any structured pattern. Some ecological and biogeographical patterns in relation to this species and its biocoenoses are discussed