Potential effect of marine traffic on white-beaked dolphin (Lagenorhynchus albirostris) distribution and behaviour in Faxaflói Bay, southwest Iceland

Faxaflói bay is a short, wide and shallow bay situated in the southwest of Iceland. Although hosting a rather high level of marine traffic, this area is inhabited by many different species of cetaceans, among which the white-beaked dolphin (Lagenorhynchus albirostris), found here all year-round. This study aimed to evaluate the potential effect of increasing marine traffic on white-beaked dolphins distribution and behaviour, and to determine whether or not a variation in sighting frequencies have occurred throughout years (2008 – 2014). Data on sightings and on behaviour, as well as photographic one, has been collected daily taking advantage of the whale-watching company “Elding” operating in the bay. Results have confirmed the importance of this area for white-beaked dolphins, which have shown a certain level of site fidelity. Despite the high level of marine traffic, this dolphin appears to tolerate the presence of boats: no differences in encounter durations and locations over the study years have occurred, even though with increasing number of vessels, an increase in avoidance strategies has been displayed. Furthermore, seasonal differences in probabilities of sightings, with respect to the time of the day, have been found, leading to suggest the existence of a daily cycle of their movements and activities within the bay. This study has also described a major decline in sighting rates throughout years raising concern about white-beaked dolphin conservation status in Icelandic waters. It is therefore highly recommended a new dedicated survey to be conducted in order to document the current population estimate, to better investigate on the energetic costs that chronic exposure to disturbances may cause, and to plan a more suitable conservation strategy for white-beaked dolphin around Iceland.

Valutazione della vulnerabilità costiera nell'area ravennate: il caso di Marina di Ravenna e foce Bevano

La tesi tratta di un concetto che negli ultimi anni sta diventando sempre più importante e per questo, deve essere studiato e analizzato: la vulnerabilità costiera. In generale per vulnerabilità si intende il carattere di chi o di ciò che è vulnerabile, ossia la sua predisposizione ad essere colpito, attaccato o danneggiato. Viene anche definita come l’attitudine di un dato elemento o contesto territoriale a supportare gli effetti di un evento dannoso in funzione dell’intensità dell’evento stesso. Questa nozione, in particolare, verrà applicata all’ambito costiero; pertanto si parlerà di vulnerabilità costiera dell’area ravennate. La vulnerabilità costiera è definita come il grado a cui un sistema costiero è suscettibile agli effetti negativi del cambiamento climatico, inclusi la variabilità climatica e gli eventi estremi. Negli ultimi decenni si è giunti alla conclusione che le manifestazioni meteo-marine di estrema entità hanno avuto la tendenza a svilupparsi con maggiore intensità e frequenza (es.: mareggiate). Questo è il motivo per cui la trattazione verterà su tale argomento, al fine di presentare, chiarire e rendere più esplicita questa tematica, sempre maggiormente presente nella realtà di tutti i giorni. Nei due siti di interesse: Marina di Ravenna e foce Bevano, sono stati effettuati due transetti, da cui sono stati estratti i relativi profili topografici, sui quali è stato calcolato il Dune Safety Factor, considerando i diversi valori di sopraelevazione marina totale.

Cryptic invertebrates on subtidal rocky reefs vary with microhabitat structure and protection from fishing

The deployment of flat concrete blocks on subtidal rocky reefs can replicate natural reef microhabitats and provides a means for standardized sampling of cryptic invertebrates. The shape of the cavity beneath the block is related to reef topography and may influence the invertebrate community by affecting the amount of space for cryptic fauna to colonise and influencing the effectiveness of their predator-defence mechanisms. To determine the effect of sub-block reef structure and different levels of external predators on cryptic molluscs and echinoderms, I deployed concrete blocks at locations inside and outside the Maria Island marine reserve in eastern Tasmania, Australia. Relationships between sub-block reef structure and the cryptic invertebrate assemblage were evident between locations, whereas only a small but significant proportion of variation of assemblages between blocks within location was explained by reef surface area. No clear association with external predation pressure was evident in multivariate analyses of variation in assemblage structure. Juvenile abalone Haliotis rubra were not influenced by micro-habitat structure but were significantly less abundant at protected locations, the only species to exhibit such a response. This result follows a decline of emergent adult abalone in the marine reserve and raises the possibility of recruitment failure of abalone at some fully protected locations in the longer term.

Association Between Atmospheric Circulation Patterns and Firn-Ice Core Records from the Inilchek Glacierized Area, Central Tien Shan, Asia

Glacioclimatological research in the central Tien Shan was performed in the summers of 1998 and 1999 on the South Inilchek Glacier at 5100 - 5460 m. A 14.36 m firn-ice core and snow samples were collected and used for stratigraphic, isotopic, and chemical analyses. The firn-ice core and snow records were related to snow pit measurements at an event scale and to meteorological data and synoptic indices of atmospheric circulation at annual and seasonal scales. Linear relationships between the seasonal air temperature and seasonal isotopic composition in accumulated precipitation were established. Changes in the delta(18)O air temperature relationship, in major ion concentration and in the ratios between chemical species, were used to identify different sources of moisture and investigate changes in atmospheric circulation patterns. Precipitation over the central Tien Shan is characterized by the lowest ionic content among the Tien Shan glaciers and indicates its mainly marine origin. In seasons of minimum precipitation, autumn and winter, water vapor was derived from the arid and semiarid regions in central Eurasia and contributed annual maximal solute content to snow accumulation in Tien Shan. The lowest content of major ions was observed in spring and summer layers, which represent maximum seasonal accumulation when moisture originates over the Atlantic Ocean and Mediterranean and Black Seas.

Long-term trends in invertebrate–habitat relationships under protected and fished conditions

Few studies examine the long-term effects of changing predator size and abundance on the habitat associations of resident organisms despite that this knowledge is critical to understand the ecosystem effects of fishing. Marine reserves offer the opportunity to determine ecosystem-level effects of manipulated predator densities, while parallel monitoring of adjacent fished areas allows separating these effects from regional-scale change. Relationships between two measures of benthic habitat structure (reef architecture and topographic complexity) and key invertebrate species were followed over 17 years at fished and protected subtidal rocky reefs associated with two southern Australian marine reserves. Two commercially harvested species, the southern rock lobster (Jasus edwardsii) and blacklip abalone (Haliotis rubra) were initially weakly associated with habitat structure across all fished and protected sites. The strength of association with habitat for both species increased markedly at protected sites 2 years after marine reserve declaration, and then gradually weakened over subsequent years. The increasing size of rock lobster within reserves apparently reduced their dependency on reef shelters as refuges from predation. Rising predation by fish and rock lobster in the reserves corresponded with weakening invertebrate–habitat relationships for H. rubra and sea urchins (Heliocidaris erythrogramma). These results emphasise that animal–habitat relationships are not necessarily stable through time and highlight the value of marine reserves as reference sites. Our work shows that fishery closures to enhance populations of commercially important and keystone species should be in areas with a range of habitat features to accommodate shifting ecological requirements with ontogenesis.

Cold-Water Coral Distributions in the Drake Passage Area from Towed Camera Observations - Initial Interpretations

Seamounts are unique deep-sea features that create habitats thought to have high levels of endemic fauna, productive fisheries and benthic communities vulnerable to anthropogenic impacts. Many seamounts are isolated features, occurring in the high seas, where access is limited and thus biological data scarce. There are numerous seamounts within the Drake Passage (Southern Ocean), yet high winds, frequent storms and strong currents make seafloor sampling particularly difficult. As a result, few attempts to collect biological data have been made, leading to a paucity of information on benthic habitats or fauna in this area, particularly those on primarily hard-bottom seamounts and ridges. During a research cruise in 2008 six locations were examined (two on the Antarctic margin, one on the Shackleton Fracture Zone, and three on seamounts within the Drake Passage), using a towed camera with onboard instruments to measure conductivity, temperature, depth and turbidity. Dominant fauna and bottom type were categorized from 200 randomized photos from each location. Cold-water corals were present in high numbers in habitats both on the Antarctic margin and on the current swept seamounts of the Drake Passage, though the diversity of orders varied. Though the Scleractinia (hard corals) were abundant on the sedimented margin, they were poorly represented in the primarily hard-bottom areas of the central Drake Passage. The two seamount sites and the Shackleton Fracture Zone showed high numbers of stylasterid (lace) and alcyonacean (soft) corals, as well as large numbers of sponges. Though data are preliminary, the geological and environmental variability (particularly in temperature) between sample sites may be influencing cold-water coral biogeography in this region. Each area observed also showed little similarity in faunal diversity with other sites examined for this study within all phyla counted. This manuscript highlights how little is understood of these isolated features, particularly in Polar regions.

Fort Richardson Ordnance Detonations and the Harbor Porpoise: A Case Study in Marine Mammal Bioacoustics

Hearing is extremely important for cetaceans because it is their “principal sense” (Weilgart, 2007) thus the harbor porpoise and other marine animals are highly dependent on sound for survival. This is why we should care about the impact of noise on animals like the harbor porpoise. Since sound travels so well in water, an explosion, sonar, boat noise, etc. can affect a very large area and thus many different species of marine mammals. Although military actions such as low frequency sonar have made recent news, noise has been affecting cetaceans, especially beaked whales, since at least 1991 (Weilgart, 2007). This study is an investigation of the possible impacts of artillery detonated on land on harbor porpoise hearing and covers some of the history of Fort Richardson, the legal and historical aspects and history of this type of concern, the science and physics of sound, marine mammal hearing and general biology of the harbor porpoise. Data were collected at the Fort Richardson Army base during June of 2007 by researchers from the University of Connecticut and the University of Rhode Island and will be used to determine the possible impacts that these detonations could have on the harbor porpoise.

Observation of manganese nodules and crusts in the Blake Plateau area

Visual observations of manganese deposits on the Blake plateau from a manned submersible indicate that the occurrence of manganese as nodules, slabs, or pavement may be related to localized environmental conditions. Manganese is concentrated at the crests of sand waves and, in areas of gentle slope, grades locally from nodules to solid pavement.

Evaluation of long chain 1,14-alkyl diols in marine sediments as indicators for upwelling and temperature

Long chain alkyl diols form a group of lipids occurring widely in marine environments. Recent studies have suggested several palaeoclimatological applications for proxies based on their distributions, but also revealed uncertainties about their applicability. Here we evaluate the use of long chain 1,14-alkyl diol indices for reconstruction of temperature and upwelling conditions by comparing index values, obtained from a comprehensive set of marine surface sediments, with environmental factors like sea surface temperature (SST), salinity and nutrient concentrations. Previous cultivation efforts indicated a strong effect of temperature on the degree of saturation and the chain length distribution of long chain 1,14-alkyl diols in Proboscia spp., quantified in the diol saturation index (DSI) and diol chain length index (DCI), respectively. However, values of these indices in surface sediments show no relationship with annual mean SST of the overlying water. It remains unknown what determines the DSI, although our data suggests that it may be affected by diagenesis, while the relationship between temperature and DCI may be different for different Proboscia species. In addition, contributions of algae other than Proboscia diatoms may affect both indices, although our data provide no direct evidence for additional long chain 1,14-alkyl diol sources. Two other indices using the abundance of 1,14-diols vs. 1,13-diols and C30 1,15-diols have previously been applied as indicators for upwelling intensity at different locations. The geographical distribution of their values supports the use of 1,14 diols vs. 1,13 diols [C28 + C30 1,14-diols]/[(C28 + C30 1,13-diols) + (C28 + C30 1,14-diols)] as a general indicator for high nutrient or upwelling conditions.