Mapping inshore fisheries: comparing observed and perceived distributions of pot fishing activity in Northumberland

PublishedJournal ArticleMarine spatial planning (MSP) is increasingly promoted as part of an ecosystem-based approach to marine resource management. Impacts of MSP may be particularly great in inshore fisheries, yet despite their vulnerability, assessing potential impacts of spatial measures on inshore fisheries is limited by data scarcity, and the comparability of patterns of fishing activity produced by different data sources is poorly understood. This study contributes to the debate around information needs for MSP by describing the distribution of lobster potting activity at four ports in Northumberland, UK, using two sources of spatial data: observed fishing vessel sightings by patrol vessels and perceived fishing activity elicited through interviews with local fishers. The comparability of the distributions of potting activity mapped by the two datasets was explored using Mantel tests and overlap of fishing hotspots identified. Fishing activity at all ports tended towards an aggregated or patchy distribution, with hotspots located in inshore areas in close proximity to vessels[U+05F3] home ports. The two datasets were correlated at each port, though the strength of correlation varied among ports, being greater in ports with more highly aggregated fishing activity. Results suggest that vessel sightings are likely to better represent variable intensity of fishing activity, while interview data may more accurately capture the absolute extent of grounds important to fishers. This study highlights some of the merits and limitations of two available data sources currently used to inform fisheries management and marine conservation planning, and outlines an approach to assessing the consistency of datasets in describing the spatial distribution of activity. Given the limitations of individual datasets, we recommend triangulation of available data to inform MSP, alongside qualitative data on fishers' behaviour

Social networks and fishers' behavior: Exploring the links between information flow and fishing success in the Northumberland lobster fishery

Fisheries worldwide are facing overexploitation, yet the social dimensions of fishers' behavior remain under-studied, and there is demand for an improved understanding of social processes that influence fisheries' dynamics. Fishers draw on social relationships to acquire information relating to fishing opportunities, contributing to knowledge that underpins decision making and behavior. In this study we use quantitative social network analysis (SNA) to compare the structure of information-sharing networks and explore links between information flow and fishing success at four ports in the Northumberland (UK) potting fishery. In our results we describe the different information-sharing networks existing at each port, and show the following: a high proportion of fishers reported sharing information, though fewer than a third of reported ties were reciprocated; subgroups existed in which greater information sharing occurred; and networks displayed varying levels of cohesiveness. Fishers commonly shared information with others whom they perceived to be successful, and reciprocal relationships were more common among fishers of similar success. Furthermore, fishers more central in networks had more sources of incoming information through social relationships, shared information with fewer peers, and were more successful than those who were less central. We conclude that engaging in information-sharing networks can provide benefits for Northumberland fishers, although advantages gained through social networks may not be equally distributed. Although informationsharing networks may contribute to fishing success, i.e., high lobster landings, these outcomes may not be compatible with long-term fisheries management objectives. Nevertheless, understanding the social dynamics of information sharing can help inform management strategies by identifying central fishers in information-sharing networks, who have access to a range of information on others' fishing behavior. Such fishers may be able to assist managers in collecting information on the distribution of fishing opportunities, the state of the fishery, and the ways in which fishers use their knowledge to adapt to change and management interventions

Development of multiple-wavelength oscillation in plasma of a pulse-periodic He+Ne+Sr laser

Mechanisms of multiple-wavelength oscillation at the lines of He I, Ne I, Sr I, and Sr II ions in the active medium of a high-voltage pulse-periodic laser based on a He + Ne + Sr mixture at a total pressure of ∼200 Torr and duration of the current pulse of about 150–300 ns are analyzed. An important role played by collisional thermal mixing of the laser levels of Ne I and Sr I in multiplets, as well as by collisions of the second kind between metastable and unexcited atoms, in populating and depopulating atomic levels is demonstrated. Absolute populations of the upper and lower levels of the laser transitions in Ne I are found. It is discovered that the degree of ionization nonequilibrium of plasma, both during and after the pulse of current, determines the mechanism of population inversion in laser transitions

Reflecting on the next generation of models for community-based natural resources management

Community-based natural resource management (CBNRM) has been a pervasive paradigm in conservation circles for three decades. Despite many potentially attractive attributes it has been extensively critiqued from both ecological and sociological perspectives with respect to theory and practice (for example Leach et al. 1999; Berkes 2004; Fabricius et al. 2004; Blaikie 2006). Nonetheless, many successful examples exist, although an equal number have seemingly not met expectations. Is this because of poor implementation or rather a generally flawed model? If the criteria and conditions for success are so onerous that relatively few projects or situations are likely to qualify, what then is the value of the model? The questions thus become: how and what can we learn from the past theory and practice to develop a new generation of flexible, locally responsive and implementable CBNRM models, and what are likely to be the attributes of such models

The PCA-seq method applied to analyze of the dynamics of COVID-19 epidemic indicators

In time series analysis using the SSA method, a univariate series is converted into the multivariate one by shifts. The resulting trajectory matrix is subjected to principal component analysis (PCA). However, the principal components can also be computed using the PCA-Seq method if segments of the original series are selected as objects. The matrix of Euclidean distances between the objects can be obtained using any method, which offers additional opportunities for time series analysis compared to the conventional SSA. In this study, the PCA-Seq method was used to analyze the dynamics of COVID-19 epidemic indicators

MPA policy: What lies behind the science?

What the current policy debate on marine protected areas (MPAs) and marine reserves (MRs) has failed to address is the fact that protection of the marine environment has as much to do with scientists, and others values as it has to do with science. To date natural science has played a dominant role in the implementation of MPAs, yet normative considerations which are embedded in the way scientists and the wider community think about the condition the marine environment should be in, and which may influence decision-making, are rarely acknowledged or discussed. This paper seeks to correct that deficiency by investigating the values that lie behind the natural science of MPAs. With the aid of epistemic community, advocacy coalition and discourse coalition theories of policy networks, this article explores the role science and scientists have played in influencing policy on MPAs at the global and national level, and looks at the extent to which normative conceptualisations within and beyond natural science have influenced the debate

STUDY ON MARKET PROCESS OF TUNA POLE-AND-LINE FISHERY IN EASTERN INDONESIA: A STUDY CASE IN SORONG, PAPUA BARAT PROVINCE

This research is a study of the way the small-scale pole-and-line tuna fishery in Sorong, Indonesia by examining official records of supply chains; key informant and fishers’ perceptions of marketing; and personal observations of landings and selling. The main finding of the study is that the pole-and-line fishers in Sorong have made strenuous efforts to escape the constrictions of middlemen by direct selling to processors.