Search results for "intertidal"
showing 7 items of 77 documents
The seaweeds <i>Fucus vesiculosus</i> and <i>Ascophyllum nodosum</i> are significant contribu…
2013
Abstract. Based on the results of a pilot study in 2007, which found high mixing ratios of molecular iodine (I2) above the intertidal macroalgae (seaweed) beds at Mweenish Bay (Ireland), we extended the study to nine different locations in the vicinity of Mace Head Atmospheric Research Station on the west coast of Ireland during a field campaign in 2009. The mean values of I2 mixing ratio found above the macroalgae beds at nine different locations ranged from 104 to 393 ppt, implying a high source strength of I2. Such mixing ratios are sufficient to result in photochemically driven coastal new-particle formation events. Mixing ratios above the Ascophyllum nodosum and Fucus vesiculosus beds …
Review of immediate cardiac response in intertidal gastropods limpets at varying temperature, salinity and air exposure
2009
In 1990 Depledge and Andresen developed a #eld/laboratory, non-invasive technique to monitor the immediate response of cardiac activity in bivalves. Since then, several researchers have experienced and tested the variability of heart beat rate (HBR)and of associated metabolic rates under di$erent conditions in intertidal molluscs. Review of HBR immediate response in acute exposure and acclimation to changes of salinity, thermal stressors and air exposure were examined to test di$erent hypothesis. In intertidal Mediterranean and tropical limpets, the decrease in metabolic rate with a decrease in salinity was di$erent in animals experiencing di$erent degrees of salinity !uctuation in their re…
Local food availability affects invasion ability of alien bivalves: an experimental and simulation integrated approach
2009
The Lessepsian bivalve Brachidontes pharaonis is considered as one of 100 worst invasive species in the Mediterranean rapidly colonizing the most part of the Basin. Its current distribution seems primarily due to ship transport of carrying larvae by ballast waters and/or in the fouling attached beneath the ship-keels. Although humanmediated transport seems to potentially in!uence dispersal of invasive species, habitat suitability, temperature, salinity and food availability (i.e. in terms of quality and quantity of organic matter) seem to represent decisive factors in determining survivorship and distribution of this species. Physiological tolerance of B. pharaonis to temperature and salini…
Heart beat rate: a physiological response to thermal stress in blue mussels species.
2009
Non-native species often have ecological impacts on invaded communities. The quanti#cation of features of invaders and recipient ecosystems facilitating and/or interfering with successful invasion remains a challenge because of several factors may in!uence the success of invasions. Among them, life history strategies (e.g., reproductive potential, body size), ability to avoid predators, disease resistance and physiological compensatory mechanisms to adapt to changing habitats are among the most important factors. The latter has been often invoked as the key to success for many intertidal invasive invertebrates and have been suggested as key indicators of invasibility rate and the ultimate d…
Scope for Growth of the intertidal Lessepsian bivalve Brachidontes pharaonis (Fischer 1870) at varying environmental variables
2009
The concept of energy available to organismal growth (i.e. scope for growth; SFG) assumes a central role in studying the behaviour of successful invaders in aquatic habitats: the higher the energy allocated to growth and reproduction, the greater the likelihood of stability/persistence in space over time of aquatic populations. When successful invaders find useful life conditions (i.e., allowing to reach maximum SFG), they compete for space and resources with indigenous species, altering the functioning of entire ecosystems. The Indo-Pacific bivalve Brachidontes pharaonis offers an excellent model for the study of “Lessepsian migration” and the successive colonization at new Mediterranean l…
Identifying suitable proxies for climate change impacts in shallow Mediterranean habitats: sponge filtration not a ready-to-use tool yet
2009
The identi#cation of reliable proxies is crucial to undertake experimental manipulation and test hypotheses on climate change impacts. We evaluated the potential use of sponge #ltering activity as a proxy for the e$ect of temperature (T) increase in shallow marine habitats since: i) Porifera are ubiquitous, sessile and long-lived aquatic organisms; ii) Porifera are active #lter feeders and play a key-role in benthic-pelagic coupling; iii) #ltering activity already proved reliable to detect T e$ects on bivalves. The systematic screening of current literature to gather data and test the assumption “T increase -> increase in sponge #ltering activity” led to a #rst list of 840 sources (title re…