title: Red Sea fish market assessments indicate high species diversity and potential overexploitation

authors: Shellem, Claire T.

subjects: artisanal fishery

abstract: In many parts of the world, particularly remote and underdeveloped regions, reports of fisheries catch, effort, and landing data are limited. In order to implement effective fishing regulations to protect natural stocks, understanding fishing pressure, key target species, catch composition, and value of each species is vital. In regions where published data is limited, and the sampling of numerous small boats and landing sites is not feasible, fish market surveys represent an opportunity to obtain key fisheries data. This study therefore aims to obtain species-specific prices and market composition for fish landed in the central Red Sea by surveying local fish markets. We conducted 11 surveys at two major Red Sea fish markets to ascertain key fisheries metrics using market data as a proxy for catch data. Results indicate that a high proportion of the market composition is generated by 46 species from six family-level groups, Serranidae, Labridae, scarine labrids, Carangidae, Lethrinidae, and Lutjanidae, contributing to 87 % of the total market biomass. Species-specific values ranged from 4.50 USD/kg to 26.44 USD/kg, with market surveys highlighting the economic value of three local serranid species: Plectropomus pessuliferus marisrubri, Plectropomus areolatus and Variola louti, all valued at more than 25 USD/kg, and a labrid: Cheilinus undulatus, valued at 26.44 USD/kg. The Serranidae family represents 47 % of the total biomass and 55 % of the potential revenue in the market, while also indicating potentially overfished reefs due to the high occurrence of smaller species and undersized individuals of higher priced serranid species. Many of the high-valued serranids were below the size at sexual maturity. Target species exhibited small body size and decreasing abundance, potentially indicating a “shrinking baseline” scenario occurring in the Saudi Arabian artisanal coral reef fishery. These results indicate that introducing effective fisheries legislation and management is necessary for the longevity and sustainability of the reef-based fishery in the Saudi Arabian Red Sea. Implementing catch quotas, size limits, and seasonal restrictions are potential mechanisms that could be used to facilitate positive change within this vulnerable fishery.

text: Red Sea fish market assessments indicate high species diversity and potential overexploitation In many parts of the world, particularly remote and underdeveloped regions, reports of fisheries catch, effort, and landing data are limited. In order to implement effective fishing regulations to protect natural stocks, understanding fishing pressure, key target species, catch composition, and value of each species is vital. In regions where published data is limited, and the sampling of numerous small boats and landing sites is not feasible, fish market surveys represent an opportunity to obtain key fisheries data. This study therefore aims to obtain species-specific prices and market composition for fish landed in the central Red Sea by surveying local fish markets. We conducted 11 surveys at two major Red Sea fish markets to ascertain key fisheries metrics using market data as a proxy for catch data. Results indicate that a high proportion of the market composition is generated by 46 species from six family-level groups, Serranidae, Labridae, scarine labrids, Carangidae, Lethrinidae, and Lutjanidae, contributing to 87 % of the total market biomass. Species-specific values ranged from 4.50 USD/kg to 26.44 USD/kg, with market surveys highlighting the economic value of three local serranid species: Plectropomus pessuliferus marisrubri, Plectropomus areolatus and Variola louti, all valued at more than 25 USD/kg, and a labrid: Cheilinus undulatus, valued at 26.44 USD/kg. The Serranidae family represents 47 % of the total biomass and 55 % of the potential revenue in the market, while also indicating potentially overfished reefs due to the high occurrence of smaller species and undersized individuals of higher priced serranid species. Many of the high-valued serranids were below the size at sexual maturity. Target species exhibited small body size and decreasing abundance, potentially indicating a “shrinking baseline” scenario occurring in the Saudi Arabian artisanal coral reef fishery. These results indicate that introducing effective fisheries legislation and management is necessary for the longevity and sustainability of the reef-based fishery in the Saudi Arabian Red Sea. Implementing catch quotas, size limits, and seasonal restrictions are potential mechanisms that could be used to facilitate positive change within this vulnerable fishery.

year: 2021

title: The physical and biological function of wood in New Zealand's forested stream ecosystems

authors: Baillie, Brenda Robin

subjects: wood

abstract: Since the arrival of humans approximately 1000 years before present (B. P.), New Zealand has lost approximately 80% of its forest cover and along with it, the contribution of wood to our aquatic ecosystems. The aim of this thesis was to undertake a large catchment-scale assessment of LW loadings, spatial distribution and morphological influence in an old-growth indigenous forest to provide some understanding on the natural characteristics of wood that would have been present in many river systems of New Zealand prior to human settlement. The second component of the thesis involved the experimental removal of wood from three small streams in order to provide some insight into what that loss of wood may have meant for fish and aquatic invertebrate communities. In the first part of the study, a catchment scale survey of large wood (LW) was completed in a 5thorder, old-growth forest river system. LW volumes ranged from 59-503 m³ ha⁻¹ and declined down the river system along with the number of LW pieces suspended across the channel and LW influence on channel morphology, whereas piece frequency, number of pieces in debris dams and length increased. Nearly half the pieces were influencing channel morphology, particularly wood accumulation, sediment storage, bank armouring, and pool formation. These key pieces were larger, longer and more stable than average. LW contribution to habitat complexity was highest in the middle to upper sections of the river system. Four key zones of wood distribution and influence were identified in the river system. Zonal boundaries were influenced by changes in transport capacity, fluvial processes and channel morphology. In the second part of the study, a field trial was established in three small forested streams to measure the influence of wood and its experimental removal on channel morphology, and indigenous fish and aquatic invertebrate communities. Prior to wood removal there were no significant differences in the total density of fish between wood pools (pools with wood cover), open pools and riffles. Total fish biomass was marginally significant with most of the fish biomass located in wood pools. At the species level, the density and biomass of banded kokopu (Galaxias fasciatus) and the weights of longfin eels (Anguilla dieffenbachii) were significantly higher in wood pools. Species richness, density and biomass of bluegill bullies (Gobiomorphus hubbsi), torrentfish (Cheimarrichthys fosteri) and the density of redfin bullies (Gobiomorphus huttoni) was highest in riffles. Differences in fish community composition were greatest between riffles and pools, whereas there was considerable overlap between the two pool types. Total invertebrate density was 70% higher in debris dams than riffles prior to wood removal, but this difference was not significant. Densities of Trichoptera (caddisfly) and Plecoptera (stonefly), and five aquatic invertebrate taxa were significantly higher in debris dams which also contained greater numbers of less common taxa (< 1% total catch) than riffles. Only Deleatidium sp. (Ephemeroptera) densities were significantly higher in riffles than in debris dams. Aquatic invertebrate communities in debris dams differed significantly from those in riffles and season had a significant influence on aquatic invertebrate community structure. Removal of wood and associated debris dams from the treatment sections in each of the three streams resulted in a simplified channel morphology, significantly increasing the length and area in riffles and reducing the area of pools. The impact on the fish community was greatest for the two larger fish, banded kokopu and large longfin eels, whose abundance declined in the treatment sections. At the reach scale, only banded kokopu biomass showed a significant decline following wood removal. Invertebrates were less affected by wood removal and associated loss of debris dams. Invertebrate composition in the remaining riffles in the treatment sections had a higher proportion of Ephemeroptera and lower proportions of Trichoptera, Plecoptera and Diptera with fewer rare species than remaining debris dams in the control sections, but there were no discernable effects on invertebrate densities and functional feeding groups at the reach scale. Public perception of wood in waterways is mainly negative and wood is managed primarily to reduce flood damage in New Zealand’s streams. With continued research and advocacy on the environmental benefits, careful planning and judicial use, there is the potential to make better use of wood to rehabilitate and enhance New Zealand’s stream environments. This thesis provides some insight into the contribution of wood to forested stream ecosystems in New Zealand and the implicit losses associated with forest removal. It also contributes to our global understanding on the role of wood, its contribution to habitat heterogeneity and influence on biological communities.

text: The physical and biological function of wood in New Zealand's forested stream ecosystems Since the arrival of humans approximately 1000 years before present (B. P.), New Zealand has lost approximately 80% of its forest cover and along with it, the contribution of wood to our aquatic ecosystems. The aim of this thesis was to undertake a large catchment-scale assessment of LW loadings, spatial distribution and morphological influence in an old-growth indigenous forest to provide some understanding on the natural characteristics of wood that would have been present in many river systems of New Zealand prior to human settlement. The second component of the thesis involved the experimental removal of wood from three small streams in order to provide some insight into what that loss of wood may have meant for fish and aquatic invertebrate communities. In the first part of the study, a catchment scale survey of large wood (LW) was completed in a 5thorder, old-growth forest river system. LW volumes ranged from 59-503 m³ ha⁻¹ and declined down the river system along with the number of LW pieces suspended across the channel and LW influence on channel morphology, whereas piece frequency, number of pieces in debris dams and length increased. Nearly half the pieces were influencing channel morphology, particularly wood accumulation, sediment storage, bank armouring, and pool formation. These key pieces were larger, longer and more stable than average. LW contribution to habitat complexity was highest in the middle to upper sections of the river system. Four key zones of wood distribution and influence were identified in the river system. Zonal boundaries were influenced by changes in transport capacity, fluvial processes and channel morphology. In the second part of the study, a field trial was established in three small forested streams to measure the influence of wood and its experimental removal on channel morphology, and indigenous fish and aquatic invertebrate communities. Prior to wood removal there were no significant differences in the total density of fish between wood pools (pools with wood cover), open pools and riffles. Total fish biomass was marginally significant with most of the fish biomass located in wood pools. At the species level, the density and biomass of banded kokopu (Galaxias fasciatus) and the weights of longfin eels (Anguilla dieffenbachii) were significantly higher in wood pools. Species richness, density and biomass of bluegill bullies (Gobiomorphus hubbsi), torrentfish (Cheimarrichthys fosteri) and the density of redfin bullies (Gobiomorphus huttoni) was highest in riffles. Differences in fish community composition were greatest between riffles and pools, whereas there was considerable overlap between the two pool types. Total invertebrate density was 70% higher in debris dams than riffles prior to wood removal, but this difference was not significant. Densities of Trichoptera (caddisfly) and Plecoptera (stonefly), and five aquatic invertebrate taxa were significantly higher in debris dams which also contained greater numbers of less common taxa (< 1% total catch) than riffles. Only Deleatidium sp. (Ephemeroptera) densities were significantly higher in riffles than in debris dams. Aquatic invertebrate communities in debris dams differed significantly from those in riffles and season had a significant influence on aquatic invertebrate community structure. Removal of wood and associated debris dams from the treatment sections in each of the three streams resulted in a simplified channel morphology, significantly increasing the length and area in riffles and reducing the area of pools. The impact on the fish community was greatest for the two larger fish, banded kokopu and large longfin eels, whose abundance declined in the treatment sections. At the reach scale, only banded kokopu biomass showed a significant decline following wood removal. Invertebrates were less affected by wood removal and associated loss of debris dams. Invertebrate composition in the remaining riffles in the treatment sections had a higher proportion of Ephemeroptera and lower proportions of Trichoptera, Plecoptera and Diptera with fewer rare species than remaining debris dams in the control sections, but there were no discernable effects on invertebrate densities and functional feeding groups at the reach scale. Public perception of wood in waterways is mainly negative and wood is managed primarily to reduce flood damage in New Zealand’s streams. With continued research and advocacy on the environmental benefits, careful planning and judicial use, there is the potential to make better use of wood to rehabilitate and enhance New Zealand’s stream environments. This thesis provides some insight into the contribution of wood to forested stream ecosystems in New Zealand and the implicit losses associated with forest removal. It also contributes to our global understanding on the role of wood, its contribution to habitat heterogeneity and influence on biological communities.

year: 2011

title: Exploring the experiences of Māori Wāhine in a STEM project-based secondary classroom: A relational and intersectional perspective

authors: Cheryl, Mitchell

abstract: Using phenomenology, an intersectional lens, and the principles of Kaupapa Māori research, this study investigates how young Māori (Indigenous) wāhine (women) ākonga (students) experience interdisciplinary project-based STEM education. Historical educational policies in Aotearoa New Zealand required Māori to assimilate into a Pākehā (European) school system, contributing to persistent academic underperformance, particularly in science. Māori have been more likely to leave school early, and those who remain often opt out of science subjects, especially Māori wāhine. International literature suggests that transdisciplinary STEM education grounded in social justice and equity can improve engagement and outcomes for underrepresented learners. The study was guided by two questions: (1) how Māori wāhine experienced the STEM programme, and (2) what their challenges were to succeed in STEM.

In 2016, while teaching at a low-decile (socioeconomic disadvantaged), urban, co-educational English-medium high school, I trialled an integrated, interdisciplinary project-based STEM class that incorporated meaningful phenomena and culturally responsive pedagogy. The class’s success led to STEM becoming a core component of a broader school initiative. In 2018, the seven Māori wāhine ākonga enrolled in the Year 11 (age 15–16) STEM class were invited to become “Story Sharers” and reflect on their experiences. As a teacher-researcher (insider), I used reflexive practices and clear role delineation to leverage contextual knowledge while minimising bias. Narrative data were collected over two years (2018–2019) through six semi-structured discussion groups and one individual interview. Quantitative data included tracking attendance records, retention, and academic achievement.

Findings indicate that the Story Sharers valued co-constructed topics and tasks, a supportive whānau (family/community) class format, and authentic project work undertaken over extended learning periods. They consistently identified strengthened relationships, particularly among peers as central to engagement, wellbeing, motivation to learn, and as the most salient indicator of success. Academic performance increased relative to prior Year-10 e-asTTle (Electronic Assessment Tool for Teaching and Learning in mathematics, reading, and writing) benchmarks, alongside improved STEM class attendance, retention in school, and intentions to continue in STEM.

Interpretive thematic analysis using an intersectional lens revealed that racism, stereotyping, and impacts on wellbeing were significant barriers to learning. These discriminatory experiences were pervasive across school, community, and online spaces and were compounded by gendered and intergenerational dynamics. The Story Sharers described complex, fluid, and intersecting identities shaped by lived experiences, including witnessing discrimination against Māori wāhine in their whānau and the legacy of colonial schooling practices such as the suppression of te reo Māori.

In this study, STEM project-based learning was shaped by two interwoven design elements: relational pedagogy and relational thinking. Relational pedagogy prioritised relationships and co-construction within a whānau-formatted classroom. Relational thinking described the interdisciplinary logic of the programme itself, connecting disciplinary knowledge to place, context, and community so that learning is organised around meaningful phenomena rather than siloed subjects. Together, these elements functioned as a counterspace that fostered inclusive engagement, affirmed identities, and supported belonging for Māori wāhine. Grounded in culturally responsive and whānau-based approaches, this model enabled learners to challenge deficit narratives and engage meaningfully in STEM. The outcomes offer assurance that integrated, project-based STEM education, underpinned by these relational frameworks, can improve outcomes for learners whose identities and experiences have been marginalised in traditional schooling. However, policymakers must remain attentive to historical policy barriers and intersectional factors that continue to perpetuate inequities within the education system.

text: Exploring the experiences of Māori Wāhine in a STEM project-based secondary classroom: A relational and intersectional perspective Using phenomenology, an intersectional lens, and the principles of Kaupapa Māori research, this study investigates how young Māori (Indigenous) wāhine (women) ākonga (students) experience interdisciplinary project-based STEM education. Historical educational policies in Aotearoa New Zealand required Māori to assimilate into a Pākehā (European) school system, contributing to persistent academic underperformance, particularly in science. Māori have been more likely to leave school early, and those who remain often opt out of science subjects, especially Māori wāhine. International literature suggests that transdisciplinary STEM education grounded in social justice and equity can improve engagement and outcomes for underrepresented learners. The study was guided by two questions: (1) how Māori wāhine experienced the STEM programme, and (2) what their challenges were to succeed in STEM.

In 2016, while teaching at a low-decile (socioeconomic disadvantaged), urban, co-educational English-medium high school, I trialled an integrated, interdisciplinary project-based STEM class that incorporated meaningful phenomena and culturally responsive pedagogy. The class’s success led to STEM becoming a core component of a broader school initiative. In 2018, the seven Māori wāhine ākonga enrolled in the Year 11 (age 15–16) STEM class were invited to become “Story Sharers” and reflect on their experiences. As a teacher-researcher (insider), I used reflexive practices and clear role delineation to leverage contextual knowledge while minimising bias. Narrative data were collected over two years (2018–2019) through six semi-structured discussion groups and one individual interview. Quantitative data included tracking attendance records, retention, and academic achievement.

Findings indicate that the Story Sharers valued co-constructed topics and tasks, a supportive whānau (family/community) class format, and authentic project work undertaken over extended learning periods. They consistently identified strengthened relationships, particularly among peers as central to engagement, wellbeing, motivation to learn, and as the most salient indicator of success. Academic performance increased relative to prior Year-10 e-asTTle (Electronic Assessment Tool for Teaching and Learning in mathematics, reading, and writing) benchmarks, alongside improved STEM class attendance, retention in school, and intentions to continue in STEM.

Interpretive thematic analysis using an intersectional lens revealed that racism, stereotyping, and impacts on wellbeing were significant barriers to learning. These discriminatory experiences were pervasive across school, community, and online spaces and were compounded by gendered and intergenerational dynamics. The Story Sharers described complex, fluid, and intersecting identities shaped by lived experiences, including witnessing discrimination against Māori wāhine in their whānau and the legacy of colonial schooling practices such as the suppression of te reo Māori.

In this study, STEM project-based learning was shaped by two interwoven design elements: relational pedagogy and relational thinking. Relational pedagogy prioritised relationships and co-construction within a whānau-formatted classroom. Relational thinking described the interdisciplinary logic of the programme itself, connecting disciplinary knowledge to place, context, and community so that learning is organised around meaningful phenomena rather than siloed subjects. Together, these elements functioned as a counterspace that fostered inclusive engagement, affirmed identities, and supported belonging for Māori wāhine. Grounded in culturally responsive and whānau-based approaches, this model enabled learners to challenge deficit narratives and engage meaningfully in STEM. The outcomes offer assurance that integrated, project-based STEM education, underpinned by these relational frameworks, can improve outcomes for learners whose identities and experiences have been marginalised in traditional schooling. However, policymakers must remain attentive to historical policy barriers and intersectional factors that continue to perpetuate inequities within the education system.

year: 2025-10-17