Tropical and Subtropical Ostreidae of the American Pacific: Fisheries, Aquaculture, Management, and Conservation

2021 ◽  
Vol 40 (2) ◽  
Author(s):  
Jorge Chávez-Villalba ◽  
José M. Mazón-Suástegui ◽  
Alfonso N. Maeda-Martínez ◽  
Ricardo García-Morales ◽  
César Lodeiros
2021 ◽  
pp. 1-16
Author(s):  
Héla Mekki

Abstract The mountain range formed by Jebels Matmata, Demmer and Nefoussa which links the two countries, Tunisia and Libya, is strewn with archaeological remains that are little known today, due in part to the rugged terrain which makes it difficult to see them. This issue has been helped by the use of new technologies, in this case remote sensing and QGIS software. Archaeological evidence has been uncovered and more than 3,900 sites and monuments have been detected on the sides of these mountains. In addition to the inventory of unknown archaeological sites, the main aim of the work was to draw up a management and conservation plan to provide, with an order of priority, a strategy for the safeguard and conservation of the mountain heritage. This management plan was only possible through a correlation of three data: assessment of values, identification of threats, and study of the state of conservation. These components were studied using an indirect evaluation based on satellite imagery and direct evaluation through field visits.


2021 ◽  
pp. 1-16
Author(s):  
FRANCISCO GUIL ◽  
M. ÁNGELES SORIA ◽  
VÍCTOR ORTEGA ◽  
RUBÉN GARCÍA-SÁNCHEZ ◽  
SILVIA VILLAVERDE-MORCILLO

Summary Avian species often take advantage of human-made structures, such as perching on power poles, although this can lead to negative effects for both birds and infrastructure. It has been demonstrated that anchor-type pylons, with strain insulators, are amongst the most dangerous of these structures. Our goal was to develop a methodological approach to evaluate the ways in which raptors perch on the six most commonly used strain insulator configurations in Spain, and to build a risk index that can be used to prioritise them. To study the ways raptors perch, we worked with six wildlife rescue centres in central Spain for almost a year assessing these six strain insulator configurations in 83 perch trials with 176 raptors in ample flying pens. We analysed 475 complete survey days, with an approximate number of 258,960 analysed pictures, including 6,766 perchings on strain insulators. We assessed the influential factors for these 6,766 perchings and developed a novel approach to prioritise strain insulator configurations that can be used anywhere. Our results suggest that longer insulator strains (i.e. PECA-1000 and Caon-C3670) are the safest, according to our prioritization criteria, although these results require further assessment in the field. Managers and conservationists should take into account these results to improve management and conservation actions.


Author(s):  
Brandi Ruscher ◽  
Jillian M. Sills ◽  
Beau P. Richter ◽  
Colleen Reichmuth

AbstractThe auditory biology of Monachinae seals is poorly understood. Limited audiometric data and certain anatomical features suggest that these seals may have reduced sensitivity to airborne sounds compared to related species. Here, we describe the in-air hearing abilities of a Hawaiian monk seal (Neomonachus schauinslandi) trained to participate in a psychophysical paradigm. We report absolute (unmasked) thresholds for narrowband signals measured in quiet conditions across the range of hearing and masked thresholds measured in the presence of octave-band noise at two frequencies. The behavioral audiogram indicates a functional hearing range from 0.1 to 33 kHz and poor sensitivity, with detection thresholds above 40 dB re 20 µPa. Critical ratio measurements are elevated compared to those of other seals. The apparently reduced terrestrial hearing ability of this individual—considered with available auditory data for a northern elephant seal (Mirounga angustirostris)—suggests that hearing in Monachinae seals differs from that of the highly sensitive Phocinae seals. Exploration of phylogenetic relationships and anatomical traits support this claim. This work advances understanding of the evolution of hearing in amphibious marine mammals and provides updated information that can be used for management and conservation of endangered Hawaiian monk seals.


2021 ◽  
Vol 13 (3) ◽  
pp. 1242
Author(s):  
Magdalena Raftowicz ◽  
Magdalena Kalisiak-Mędelska ◽  
Mirosław Struś

Community Supported Agriculture (CSA) is an alternative form of distributing agricultural products, including fish, consistent with the model of food supply chain shortening. It extends beyond the traditional model of profit maximization and aims at strengthening local interactions with food consumers. The purpose of this article is to assess the feasibility of implementing the CSA model in the Polish carp market, representing the dominant aquaculture product. The research focused on the potential identified on the supply and demand sides of the carp market. The source material was collected through a pilot two-track empirical study conducted in 2019 in the Barycz Valley, where the largest complex of carp breeding ponds is located in Poland, and in Europe. We propose that the following CSA model of direct sales can become a source of specific benefits in the economic, social, and environmental dimensions for the key stakeholders of the supply chain, (i.e., carp producers and consumers). The research results show that in the case of carp production in Poland, CSA may turn out a desirable support for the sale of fish in the future; however, the existing conditions are not yet fully favourable for its development.


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