scholarly journals Summer Abundance of Harbour Porpoises (Phocoena phocoena) in the Coastal Waters of Iceland and the Faroe Islands

2020 ◽  
Vol 11 ◽  
Author(s):  
Anita Gilles ◽  
Thorvaldur Gunnlaugsson ◽  
Bjarni Mikkelsen ◽  
Daniel G. Pike ◽  
Gísli A. Víkingsson
Keyword(s):  
Coastal Waters ◽  
Harbour Porpoise ◽  
Line Transect ◽  
Faroe Islands ◽  
Phocoena Phocoena ◽  
The North ◽  
Counting Procedure ◽  
Abundance Estimates ◽  
By Catch ◽  
The Impact

This study presents the first fully corrected abundance estimates for the harbour porpoise (Phocoena phocoena) for Iceland and the Faroe Islands. In both regions reliable estimates are needed to assess the impact of by-catch and other threats to harbour porpoises. Aerial surveys with harbour porpoise as a secondary and main target species were conducted in the summers of 2007 and 2010 in Icelandic and in Faroese coastal waters respectively. In Iceland, the cue counting procedure was used (which also produces the data required for line transect analysis), while in the Faroese, standard line transect sampling was applied, following the SCANS-II (Small Cetacean Abundance in the North Sea) survey protocol. In both surveys, identical aircraft surveyed at an altitude of 600 ft and a speed of 90–100 kn. Only data collected during Beaufort Sea States (BSS) lower than 3 and during good or moderate porpoise sighting conditions were used for abundance estimates. Abundance estimates were corrected using stratified estimates of esw (incorporating g(0)) values derived during the SCANS-II survey in 2005 as principal observers took part in this survey as well. In Iceland, realised effort in good or moderate harbour porpoise sighting conditions totalled 8,289 km in 13 survey strata, where 77 sightings (109 individuals) were made by the experienced harbour porpoise observer only. In Faroese waters, only part of the area inside the 300 m depth curve could be surveyed and 1,564 km were surveyed in good or moderate porpoise sighting conditions, yielding 39 sightings (49 individuals). The total abundance estimates were 43,179 porpoises (CV=0.45; 95% CI: 31,755–161,899) for Icelandic coastal waters and 5,175 porpoises (CV=0.44; 95% CI: 3,457–17,637) for Faroese waters.

scholarly journals Harbour porpoise (Phocoena phocoena) in the North Atlantic: Abundance, removals, and sustainability of removals

2003 ◽  
Vol 5 ◽  
pp. 271 ◽  
Author(s):  
G B Stenson
Keyword(s):  
North Atlantic ◽  
Harbour Porpoise ◽  
Phocoena Phocoena ◽  
The North ◽  
Number Of Factors ◽  
The Status ◽  
Substantial Progress ◽  
Potential Population ◽  
The North Atlantic ◽  
The Impact

The status of harbour porpoise (Phocoena phocoena) populations in the North Atlantic has raised numerous concerns. Although a number of factors that may be adversely affecting harbour porpoise populations have been identified, focus has been on the impact of removals, primarily due to incidental catches in fishing gear. As a result, considerable efforts have been made to determine the levels and/or impact of bycatch in a number of areas. Unfortunately, many areas remain little studied. Currently, harbour porpoise are listed as threatened or vulnerable in many parts of their range. In order to determine if the current levels of removals are sustainable, information on stock identity and seasonal movements, population parameters, abundance, and the magnitude of removals is required. Although substantial progress has been made to improve our knowledge of these parameters in the last decade, significant gaps still exist. After reviewing the available data for each sub-population in the North Atlantic, it is clear that the information required to assess the status of harbour porpoise populations is still not available for most areas. Attempts have been made to assess the status of harbour porpoise based on trends in sightings or, in areas where information on abundance and bycatch are available, on models using arbitrary criteria and/or theoretical estimates of potential population growth. Detailed case-specific population models have been proposed but are not yet available.

Mitigation of harbour porpoise (Phocoena phocoena) by-catch in the gillnet fishery in the lower Bay of Fundy

1999 ◽  
Vol 56 (1) ◽  
pp. 113-123 ◽  
Author(s):  
Edward A Trippel ◽  
Michael B Strong ◽  
John M Terhune ◽  
Jeremy D Conway
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Field Testing ◽  
Harbour Porpoise ◽  
Clupea Harengus ◽  
Bay Of Fundy ◽  
Phocoena Phocoena ◽  
By Catch ◽  
Catch Rates ◽  
Wind Sea

Demersal gill nets equipped with acoustic alarms reduced harbour porpoise (Phocoena phocoena) by-catch rates by 77% over those without alarms in the Swallowtail area of the lower Bay of Fundy during field testing in August 1996 (68% reduction) and 1997 (85% reduction) (both years combined, three harbour porpoises in 249 alarmed nets versus 14 harbour porpoises in 267 nonalarmed nets). The alarms spaced 100 m apart along the net floatline produced a 0.3-s pulse at 10-12 kHz every 4 s at a level of 133-145 dB re 1 µPa at 1 m. In conditions of no rain and low wind (Sea State 0-2) the alarms were presumed to be clearly audible to harbour porpoises at ranges of 0.1-0.6 km. Catch rates of Atlantic herring (Clupea harengus), Atlantic cod (Gadus morhua), and pollock (Pollachius virens) were not significantly different in alarmed and nonalarmed nets (except in one season when pollock were caught in lower numbers in alarmed nets). Harbour porpoise by-catch and herring movements may be linked. During years of low herring abundance, we also observed low harbour porpoise entanglement rates.

Harbour porpoises (Phocoena phocoena) in north-western France: aerial survey, opportunistic sightings and strandings monitoring

2009 ◽  
Vol 89 (5) ◽  
pp. 1045-1050 ◽  
Author(s):  
J.-L. Jung ◽  
E. Stéphan ◽  
M. Louis ◽  
E. Alfonsi ◽  
C. Liret ◽  
...  
Keyword(s):  
North Sea ◽  
Aerial Survey ◽  
Harbour Porpoise ◽  
Shallow Waters ◽  
Encounter Rate ◽  
English Channel ◽  
Phocoena Phocoena ◽  
The North ◽  
The North Sea ◽  
North Western

The harbour porpoise (Phocoena phocoena) is one of the common small cetaceans of European waters. This discreet and undemonstrative species is strongly represented throughout the cold waters of the northern hemisphere, and is the most abundant cetacean in the North Sea. In the last few years, some observations and studies indicate a shift of harbour porpoise distribution in European waters, from northern regions of the North Sea to the southern North Sea, English Channel and Celtic Sea. This shift may include a comeback around the coasts of France. Harbour porpoises inhabit shelf-waters and are often observed in shallow waters, conditions offered for instance by the coasts of Brittany in north-western France. We used opportunistic sightings, aerial survey and a ten-year strandings database to study the presence of harbour porpoises along the coasts of Brittany. Opportunistic sightings made by non-specialists did not confirm a strong presence of harbour porpoises along the Brittany coasts, most probably because of the undemonstrative behaviour of this cetacean. However, aerial survey and stranding analysis indicate that harbour porpoises have become natural inhabitants of the Brittany coasts once more: 68.6% of cetacean school sightings made during a 1578 km aerial survey of the Brittany coasts concerned harbour porpoises, with an encounter rate of 1.5 individuals per 100 km that peaked to 5.8 per 100 km to the top of the shallow waters of the south-western Western English Channel. The number of harbour porpoise strandings increased each year from 1997 to 2007, making a total of 135 along the coasts of Brittany. Other cetaceans did not show such an increase during the same period. Strandings of harbour porpoises were also characterized by an apparent increase as a proportion in relation to all the cetacean strandings during the months of September to January, by a marked impact of by-catch during winter, and by an almost total absence of stranded calves. The comeback of the harbour porpoise along Brittany coasts is clearly confirmed by our data, and a stable population seems to be established again along the coasts of Brittany. This tends to confirm the shift of the distribution of the species in certain European waters. Long term monitoring, diet and genetic studies are now planned for a better understanding of this shift, and for the effective implementation of a conservation plan.

Identification of the first harbour porpoise (Phocoena phocoena) calving ground in the North Sea

1999 ◽  
Vol 41 (3) ◽  
pp. 225-232 ◽  
Author(s):  
R.P Sonntag ◽  
H Benke ◽  
A.R Hiby ◽  
R Lick ◽  
D Adelung
Keyword(s):  
North Sea ◽  
Harbour Porpoise ◽  
Phocoena Phocoena ◽  
The North ◽  
The North Sea

scholarly journals The harbour porpoise (Phocoena phocoena) in the North Atlantic: Variability in habitat use, trophic ecology and contaminant exposure

2003 ◽  
Vol 5 ◽  
pp. 223 ◽  
Author(s):  
Arne Bjørge
Keyword(s):  
Habitat Use ◽  
North Atlantic ◽  
Coastal Waters ◽  
Trophic Ecology ◽  
Point Sources ◽  
Phocoena Phocoena ◽  
Cetacean Species ◽  
Contaminant Exposure ◽  
The North ◽  
Management Plans

Harbour porpoises inhabit coastal waters, in habitats that are characterized by high diversity and complexity in terms of their bathymetry, substrate, fish communities and point sources of contaminants. The complexity in these habitats influences both the habitat use and feeding ecology of porpoises. Congregations of porpoises feeding primarily on one species are observed in some areas and seasons, while wide movements and diets composed of several species are observed in other areas. Due to these observations, this paper suggests that caution is needed when extrapolatingknowledge from one area to another with regard to porpoise habitat use, exposure to contaminants, and interactions with fisheries. Management plans should be site specific and based on local knowledge incorporating porpoise population structure, habitat use, and multiple environmental factors in order to ensure appropriate conservation of this abundant but still vulnerable small cetacean species.

scholarly journals Simulation of impact of organic and nutrient pollutants from Nghi Son economic zone on Thanh Hoa coastal waters, North Centre Vietnam

2021 ◽  
Vol 21 (1) ◽  
pp. 23-36
Author(s):  
Hai Nguyen Minh ◽  
Vinh Vu Duy
Keyword(s):  
Coastal Waters ◽  
Current Status ◽  
North Central ◽  
Waste Discharge ◽  
The North ◽  
Pollutant Concentrations ◽  
Numeric Modeling ◽  
Economic Zone ◽  
Surrounding Areas ◽  
The Impact

Nghi Son is an economic zone oriented to developing heavy industry and petrochemicals and has potential to become the most substantial economic zone in the North Central region. The zone is also one of the potential waste sources polluting Thanh Hoa coastal waters. Numeric modeling using Delft3D software package with different scenarios: Current status scenario, controlled discharge scenario, and incident scenario was developed to simulate states of some pollutants of organics and nutrients from the zone to Thanh Hoa coastal waters in different periods. The simulation results show that under controlled discharge (increasing pollutant concentration with the control of waste discharge), the concentration of pollutants was increasing and high around discharging points. In contrast, in incident case from the zone, pollutant concentrations increase markedly both in the magnitude and in the impact range to surrounding areas. When an accident happens, the influence scale will be expanded significantly, especially in the rainy season.

An Integral Approach to Support Managerial Actions on Micropollutants in the Southern North Sea

1991 ◽  
Vol 24 (10) ◽  
pp. 29-38 ◽  
Author(s):  
A. Roos ◽  
J. F. M. van Vliet ◽  
J. A. van Pagee ◽  
T. A. Nauta ◽  
M. B. de Vries
Keyword(s):  
North Sea ◽  
Coastal Waters ◽  
Waste Water Treatment ◽  
Anthropogenic Pollution ◽  
Integrated Modelling ◽  
Integral Approach ◽  
The North ◽  
Modelling Framework ◽  
Dredging Sludge ◽  
The Impact

During the last decades the southern part of the North Sea has been exposed to high inputs of micropollutants from various sources. Within the framework of the project Management Analysis North Sea (MANS), studies have been carried out to quantify the impact of anthropogenic pollution inputs on coastal water quality, sediments and biota. In order to study the effects of different managerial actions an integrated modelling framework has been developed to enable a spatial evaluation. In this regard special attention has been given to:–the reduction of river inputs, as a result: of domestic and industrial waste water treatment–the storage of dredging sludge from the Rhine-Meuse estuary. It is shown by the results of this study that input reductions of heavy metals since 1980 have resulted in a significant reduction of concentrations in Dutch coastal waters. Long-term simulation of accumulation of pollutants in the sediment, however, showed that due to the long time scale the reduction of the seabed can take several decades. Similar conclusions can be drawn for organic micropollutants, although the input reductions seem to be less pronounced. Based on bioaccumulation modelling, the pollution of the sediment proved to be an important source for uptake of micropollutants in the food web. This study also made clear that significant reductions of North Sea pollution can be established if combined actions are taken. Reduction of pollutants from the Rhine-Meuse estuary, together with the storage of polluted dredging sludge from the Rotterdam harbours, will result in a significant reduction of the state of pollution of the coastal waters of the Netherlands.

First photographed observation of the harbour porpoise (Phocoena phocoena) in Svalbard

Polar Record ◽  
2007 ◽  
Vol 43 (1) ◽  
pp. 73-74
Author(s):  
Morten Joergensen
Keyword(s):  
High Arctic ◽  
Harbour Porpoise ◽  
North Coast ◽  
Phocoena Phocoena ◽  
Arctic Species ◽  
The North ◽  
Species Being

The first photographed observation of the harbour porpoise in Svalbard is reported. The harbour porpoise is not normally found in the high Arctic as it is a temperate and sub Arctic species, the nearest frequent location for the species being the north coast of Norway.

scholarly journals Trends in the distribution and abundance of cetaceans from aerial surveys in Icelandic coastal waters, 1986-2001

2009 ◽  
Vol 7 ◽  
pp. 117 ◽  
Author(s):  
Daniel G Pike ◽  
Charles GM Paxton ◽  
Thorvaldur Gunnlaugsson ◽  
Gísli A Víkingsson
Keyword(s):  
Relative Abundance ◽  
Minke Whale ◽  
Humpback Whales ◽  
Line Transect ◽  
Survey Area ◽  
Balaenoptera Acutorostrata ◽  
The North ◽  
Aerial Surveys ◽  
Minke Whales ◽  
Abundance Estimates

Aerial surveys were carried out in coastal Icelandic waters 4 times between 1986 and 2001 as part of the North Atlantic Sightings Surveys. The surveys had nearly identical designs in 3 of the 4 years. The target species was the minke whale (Balaenoptera acutorostrata) but all species encountered were recorded. Sighting rate and density from line transect analysis were used as indices of relative abundance to monitor trends over the period, and abundance estimates corrected for perception biases were calculated for some species from the 2001 survey. More than 11 species were sighted, of which the most common were the minke whale, humpback whale (Megaptera novaeangliae), dolphins of genus Lagenorhychus, and the harbour porpoise (Phocoena phocoena). Minke whales anddolphins showed little change in distribution or abundance over the period. There were an estimated 31,653 (cv 0.30) dolphins in the survey area in 2001. Humpback whales increased rapidly at a rate of about 12%, with much of the increase occurring off eastern and northeastern Iceland. In 2001 there were an estimated 4,928 (cv 0.463) humpback whales in the survey area. The relative abundance of harbour porpoises decreased over the period, but estimates for this species were compromised by uncorrected perception biases and poor coverage. The ecological and historical significance of these findings with respect to previous whaling activities and present-day fisheries is discussed.

Sign in / Sign up

Export Citation Format

Share Document