Cryptic diversity and limited connectivity in octopuses: Recommendations for fisheries management.

The market demand for octopus grows each year, but landings are decreasing, and prices are rising. The present study investigated (1) diversity of Octopodidae in the Western Indian Ocean (WIO) and (2) connectivity and genetic structure of Octopus cyanea and O. vulgaris populations in order to obtain baseline data for management plans. A fragment of the cytochrome C oxidase subunit 1 (COI) gene was sequenced in 275 octopus individuals from Madagascar, Kenya and Tanzania. In addition, 41 sequences of O. vulgaris from South Africa, Brazil, Amsterdam Island, Tristan da Cunha, Senegal and Galicia were retrieved from databases and included in this study. Five different species were identified using DNA barcoding, with first records for O. oliveri and Callistoctopus luteus in the WIO. For O. cyanea (n = 229, 563 bp), 22 haplotypes were found, forming one haplogroup. AMOVA revealed shallow but significant genetic population structure among all sites (ϕST = 0.025, p = 0.02), with significant differentiation among: (1) Kanamai, (2) southern Kenya, Tanzania, North and West Madagascar, (3) Southwest Madagascar and (4) East Madagascar (ϕCT = 0.035, p = 0.017). For O. vulgaris (n = 71, 482 bp), 15 haplotypes were identified, forming three haplogroups. A significant genetic population structure was found among all sites (ϕST = 0.82, p ≤ 0.01). Based on pairwise ϕST-values and hierarchical AMOVAs, populations of O. vulgaris could be grouped as follows: (1) Brazil, (2) Madagascar and (3) all other sites. A significant increase in genetic distance with increasing geographic distance was found (Z = 232443, 81 r = 0.36, p = 0.039). These results indicate that for O. cyanea four regions should be considered as separate management units in the WIO. The very divergent haplogroups in O. vulgaris from Brazil and Madagascar might be evolving towards speciation and therefore should be considered as separate species in FAO statistics

Fishing site mapping using local knowledge provides accurate and satisfactory results: Case study of Octopus fisheries in Madagascar

Accurate fishing ground maps are necessary for fisheries monitoring. In Velondriake locally managed marine area (LMMA) we observed that the nomenclature of shared fishing sites (FS) is villages dependent. Additionally, the level of illiteracy makes data collection more complicated, leading to data collectors improvising when recording FS. In this case study for Velondriake we opted for a participatory approach giving special consideration to local knowledge in mapping octopus fishing grounds. Other techniques (single or multiple GPS points) have been tried but gave overlapping maps for neighboring FS, and do not reflect reality. Local fishers know the exact extent of their fishing grounds and are able to draw them accurately. We utilized a printed habitat map or Google Earth satellite imagery, and asked fishers to draw in each FS. Using this technique, 325 sites were identified from 13 villages, without any overlaps or duplications, making a valuable contribution to fisheries management efforts. This supports the contention that local knowledge, and the participation of local fishers, is crucial in conservation. This approach strengthens the relationship between scientists, managers and local communities. This technique is cost effective and adaptable to each situation, and is now widely used by Malagasy fishing communities.

A social network analysis of mangrove management stakeholders in Sri Lanka's Northern Province

The sustainable management of complex social-ecological systems (SES) typically requires coordination and collaboration between various groups of stakeholders. Yet, research on collaborative stakeholder networks and their linkages with sustainable mangrove management strategies is lacking in Sri Lanka. This study presents a social network analysis (SNA) of mangrove management stakeholders and their perceptions of both existing and preferred collaborative relationships (or ties) between stakeholder groups, in the Northern Province of Sri Lanka. It further illustrates how SNA can be used to identify stakeholder collaboration and their potential role(s) in mangrove management. The perspectives of all key stakeholders have an impact on how mangroves need to be managed. Therefore, it is crucial to identify and meet with all key stakeholders in the early stages of management processes to understand their needs and constraints. Our findings indicate that the government departments mandated to conserve mangroves are not only formally appointed key stakeholders but are also perceived as central by others. Communication barriers, lack of awareness regarding the importance of mangroves, and shortages in staff and resources for conservation were major constraints to the existing mangrove management network. We highlight the potential of other stakeholders (i.e., non-mandated government stakeholders, non-governmental organizations (NGOs), and private organizations) in improving and influencing the social network in order to increase the diffusion of information. Despite existing resource extraction activities, private organizations were less represented in the mangrove management network of our study. After considering stakeholders’ expectations and requirements, we suggest the inclusion of a bridging organization such as an “Environment Network Unit” or the establishment of bridging entities in the universities and research institutes. We also recommend certain government organizations (i.e., Central Environmental Authority) to take up the role of bridging. This may help to facilitate the incorporation of relatively marginalized stakeholders in an effort to foster sustainable mangrove management in the Northern Province of Sri Lanka and beyond

Expansion of the mangrove species Rhizophora mucronata in the Western Indian Ocean launched contrasting genetic patterns

Estimates of population structure and gene flow allow exploring the historical and contemporary processes that determine a species’ biogeographic pattern. In mangroves, large-scale genetic studies to estimate gene flow have been conducted predominantly in the Indo-Pacific and Atlantic region. Here we examine the genetic diversity and connectivity of Rhizophora mucronata across a > 3,000 km coastal stretch in the Western Indian Ocean (WIO) including WIO islands. Based on 359 trees from 13 populations and using 17 polymorphic microsatellite loci we detected genetic breaks between populations of the (1) East African coastline, (2) Mozambique Channel Area (3) granitic Seychelles, and (4) Aldabra and northern Madagascar. Genetic structure, diversity levels, and patterns of inferred connectivity, aligned with the directionality of major ocean currents, driven by bifurcation of the South Equatorial Current, northward into the East African Coastal Current and southward into the Mozambique Channel Area. A secondary genetic break between nearby populations in the Delagoa Bight coincided with high inbreeding levels and fixed loci. Results illustrate how oceanographic processes can connect and separate mangrove populations regardless of geographic distance.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Mangrove management in Sri Lanka and stakeholder collaboration: A social network perspective

Understanding the extent of collaboration among stakeholders is key to supporting mangrove management. Despite the existence of robust policies, collaboration among stakeholders of mangrove co-management remains largely unexplored in Sri Lanka. This was partly due to the civil war, natural disasters, and other socio-economic changes over the past 30 years. Our study aimed to identify the collaboration between stakeholders of mangrove management and their perceptions regarding mangrove co-management in Sri Lanka using social network analysis and content analysis. Surveys were conducted in all five coastal provinces of Sri Lanka. Stakeholders included in the study were from government departments, non-governmental organizations, and private institutes. Our results showed that there were differences between coastal provinces in the mangrove management networks, specifically in the number of stakeholders involved and their degree of collaboration. Some important stakeholders (for example the Land Use and Policy Planning Department) were excluded from the social networks in certain provinces (Eastern and Western provinces). There were various issues hampering effective mangrove management such as inefficient communication, inconsistencies between policies, and insufficient financial capacity of government stakeholders responsible for policy implementation. According to the stakeholders in our study, providing mangrove management initiatives with long-term collaboration, post-care, continuous monitoring, and funding may help to overcome these challenges. Additionally, we suggest the establishment of a common platform to coordinate stakeholders. We further encourage increasing the participation of academics, researchers, and students from national universities in the mangrove co-management of Sri Lanka. Insights from this island-wide survey can be adapted to mangrove and other natural resource management trajectories in other countries as well

The Mangal Play: A serious game to experience multi-stakeholder decision-making in complex mangrove social-ecological systems

In order to achieve collaborative action in nature conservation and natural resources management, stakeholders have to understand and acknowledge other stakeholders’ interests, values, world visions and objectives and they have to overcome the problem of irrational decision-making through innate opposition discourses. In this paper we developed the Mangal Play, an experiential learning method to have participants adopt the role of a particular stakeholder in an imaginary mangrove forest social-ecological system (SES). The Mangal Play is a serious game, more specifically a role-play, aimed at promoting oral dialogues between 20 stakeholders involved in governance, fisheries, aquaculture, agriculture, forestry, tourism, transport, conservation and communication sectors. By providing tools to lecturers and scientists to execute it in a public or classroom setting, the Mangal Play stimulates a decision-making process while accepting compromise and distinguishing bottom-line issues from negotiable positions, and instructs about the behaviour of complex real-world systems in a safe learning environment. We exemplify how social network analysis can serve to visualise the outcome and further develop the Mangal Play. In this way we hope to help stakeholders take into account diverse positions in a rational decision-making process