scholarly journals Spawning aggregations of fish in Cabo Delgado, Northern Mozambique: An interview-based survey of artisanal fishers

2020 ◽  
Vol 19 (1) ◽  
pp. 33-43
Author(s):  
Sidonio Machaieie ◽  
Isabel M. Silva

Seasonal aggregations at specific sites are common among some fish species. Experienced fishermen know where and when these aggregations happen, often targeting these spawning sites to increase their catch. This strategy can further contribute to endangering the survival of these species, especially for those already threatened by other forms of pressure. This study contributes knowledge to the spawning aggregation of fish in the north of Mozambique following survey work conducted around Cabo Delgado Province in six coastal villages in 2016, 2017 and 2018. The objectives of the study were 1) to identify the species and sites of spawning aggregation and 2) to determine the timing of spawning aggregations. Data collection consisted of interviews targeting the most experienced fishermen to obtain information on these subjects. The results indicate that out of 124 fishermen interviewed, 59% had knowledge of spawning aggregations. The information collected from fisher interviews revealed that there are at least six spawning locations and at least eight species aggregate to spawn (Leptoscarus vaigensis, Lethrinus harak, Lethrinus nebulosus, Lethrinus obsoletus, Lethrinus olivaceus, Plectorhinchus gaterinus, Plectorhinchus schotaf, Siganus sutor). Only Siganus sutor was reported to spawn in at least one of the fishing areas used by every village. The timing of spawning aggregations most reported by fishermen was during the Kusi (South) monsoon period.

2012 ◽  
Vol 63 (12) ◽  
pp. 1255 ◽  
Author(s):  
Adrian J. Flynn ◽  
John R. Paxton

A spawning aggregation of the lanternfish Diaphus danae in the Coral Sea, that is fed on by spawning aggregations of yellowfin and bigeye tuna, has been sampled by mid-water trawling for the first time. Males and females in the aggregation occurred at a ratio of 23 to 1 and occupied two non-overlapping size classes (males 71.2–95.1-mm standard length (SL), females 99.0–121.4-mm SL). Hydrated oocytes with single oil droplets, which indicated imminent spawning, were in higher proportion in the first trawl (2134 hours to 2234 hours) than in the final trawl (0324 hours to 0424 hours) through the aggregation. Maximum estimated female D. danae fecundity (25 803) and gonadosomatic index (34.01) were higher than for any other lanternfish species recorded. Bigeye tuna (Thunnus obesus) individuals collected from aggregations were estimated to have 81–319 D. danae specimens in their stomachs. The annual Coral Sea D. danae aggregation is the only confirmed lanternfish spawning aggregation in Australian waters. The D. danae spawning aggregation provides a rich, transient foraging resource for spawning bigeye and yellowfin tuna in the Coral Sea, these being the only known tuna spawning aggregations in the Eastern Tuna and Billfish Fishery.


2020 ◽  
Vol 33 ◽  
pp. 15
Author(s):  
Roi Martínez-Escauriaza ◽  
Claudio Vieira ◽  
Lídia Gouveia ◽  
Nuno Gouveia ◽  
Margarida Hermida

Data obtained from licenses of spearfishers and surveys conducted in 2004 and 2017 allowed for the analysis, for the first time, of the practice of spearfishing in the Madeira archipelago. Only a small percentage of the population practices spearfishing, mostly local young men. Most of them practice the activity with a partner throughout most of the year and along most of the island's coastal areas, although preferentially along the North and Southeast coast. Results show how, in recent years, despite the population of spearfishers decreasing, the abundance in the annual catch potentially increased, probably due to the higher investment of time in this activity. It has been observed that many fishers complement their catches with manual collecting of invertebrates. Overall, 40 teleost fishes and also 4 crustaceans and 8 molluscs were identified. The most frequently captured fish species were parrotfish and white seabream, while limpets were the most collected invertebrates in both selected periods.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Daniel da Silva Ladislau ◽  
Maiko Willas Soares Ribeiro ◽  
Philip Dalbert da Silva Castro ◽  
Jackson Pantoja-Lima ◽  
Paulo Henrique Rocha Aride ◽  
...  

Abstract Background The capture of ornamental fish is one of the main economic activities of riverine families in the Amazon. However, studies regarding the local ecological knowledge of workers in this activity are still incipient. In view of this, we have studied and explored the local ecological knowledge of artisanal fishers who specialize in the capture of fish for the aquarium trade in the middle part of the Negro River basin and investigated issues related to the ecological aspects of the fish species that are targeted by this trade in the region. Methods Therefore, we conducted semi-structured interviews and applied questionnaires to artisanal fishers of ornamental fish (N = 89), from the municipality of Barcelos, from January to April 2016. Results In total, 41 popular names were cited, which correspond to four ethnocategories and 10 families. The main species were Paracheirodon axelrodi (12.5%), Hemigrammus bleheri (8.3%), Ancistrus dolichopterus (6.4%), Symphysodon discus (5.3%), and Potamotrygon motoro (3.8%). According to the fishers, the species of fish known in the region as “piabas” have a preference for living in clusters (28.9%) and carry out migratory movements (26.1%). The diet of local fish species reported by fisheries is diverse, though mainly based on periphyton (42.2%), and the reproductive cycle directly influenced by the period of flooding of rivers in the region (37.6%) Conclusion Our study revealed that the fishers possess information on the ecological aspects of local ornamental fish species, many of which are consistent with scientific literature. The information presented may assist in the decision-making process for the management of local fishery resources and contribute to the resumption of growth and sustainability in the capture of ornamental fish.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Cassandra R. Davis ◽  
Sarah R. Cannon ◽  
Sarah C. Fuller

PurposeThe purpose of this paper is to identify and describe the long-term impacts of hurricanes on schools and discuss approaches to improving recovery efforts.Design/methodology/approachInterviews with 20 school districts in Texas and North Carolina after Hurricanes Harvey (2017) and Matthew (2016). In total, 115 interviews were conducted with teachers, principals, district superintendents and representatives from state education agencies. Interview questions focused on the impact of storms and strategies for recovery.FindingsThe authors uncovered three long-term impacts of hurricanes on schools: (1) constrained instructional time, (2) increased social-emotional needs and (3) the need to support educators.Research limitations/implicationsThis paper focuses on two storms, in two states, in two successive years. Data collection occurred in Texas, one academic year after the storm. As compared to the North Carolina, data collection occurred almost two academic years after the storm.Practical implicationsThis paper illuminates strategies for stakeholders to implement and expedite hurricane recovery through; (1) updating curricula plans, (2) providing long-term counselors and (3) supporting educators in and out of school.Originality/valueTo date, very few studies have explored the ways in which schools face long-term impacts following a disaster. This paper provides insight to the challenges that prolong the impacts of disasters and impede recovery in schools. With hurricanes and related disasters continuing to affect schooling communities, more research is needed to identify the best ways to support schools, months to years after an event.


2018 ◽  
Vol 142 ◽  
pp. 132-146 ◽  
Author(s):  
Jacqueline D. Eggleton ◽  
Jochen Depestele ◽  
Andrew J. Kenny ◽  
Stefan G. Bolam ◽  
Clement Garcia

2021 ◽  
Vol 2 (1) ◽  
pp. 6.1-6.16
Author(s):  
Natalie Robertson

This article considers how Indigenous stories and chants can tell us about our ecologies in the time of environmental emergencies. For Ngāti Porou of the lower reaches of the Waiapu river catchment in Te Ika-a-Māui, the North Island of Aotearoa (New Zealand), the slow catastrophes of twentieth-century colonial deforestation impacts, introduced pest-induced inland forest collapse and predicted twenty-first-century climate change sea level rise have converged as our most pressing environmental problems. Waiapu is home to Ngāti Porou Tūturu, coastal fishing people who value their relationships with fish species, notably kahawai. The mōteatea chant form acts as a guide to my photographic and moving image practice to visualize and voice the slow catastrophe of the river. In this article, I discuss how the Ngāti Porou mōteatea He Tangi mo Pāhoe, which reveals nineteenth-century ecological knowledge, particularly of fish species, is reimagined as a moving image visual mōteatea. Through reframing the threats as the current faces of our ancestors, this article proposes a shift in thinking from vulnerability into resilience.


2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Kristoforus Slamet Suryadi Junardi, Tri Rima Setyawati

Diversity of fish species is important  known to determinate river. The purpose of this study was to determine the diversity and distribution of fish also environmental conditions in the lower reaches of the Sekadau River, West Kalimantan. Data collection is conducted from March to May 2018 using posat and gill net. The results showed that the most common Cyprinidae family was found in Rasbora argyrotaenia  and Osteochilus microcephalus with dominance value  0.72 and 0.70 respectively.


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