title: Management strategies to optimise sustainable clam (Tapes philippinarum) harvests in Barbamarco Lagoon, Italy

authors: Spillman, C.M.

subjects: tapes philippinarum

abstract: Barbamarco Lagoon is a small lagoon adjoining the Northern Adriatic Sea and is the site of a commercially valuable clam (Tapes philippinarum) fishery. A three-dimensional (3D) coupled hydrodynamic–ecological model was applied to the lagoon with the objective of assessing impacts on clam food supply, commercial harvests and water quality of different clam rearing strategies, lagoon morphologies and flow regimes. Harvest and net growth to seeding ratios, total harvest value, clearance efficiencies and clam satiety were used to quantify the commercial success of different management strategies, while bottom dissolved oxygen concentrations were used as an indicator of ecosystem health. Increasing exchange with the Northern Adriatic Sea or increasing freshwater inputs into the lagoon improved clam food supply and increased both harvest production and ecosystem health in model simulations of the system. Results indicated that the high spatial and temporal variability of clam production and water quality responses must be considered for a holistic assessment of the outcomes of strategies in the context of ecological and production carrying capacity.

text: Management strategies to optimise sustainable clam (Tapes philippinarum) harvests in Barbamarco Lagoon, Italy Barbamarco Lagoon is a small lagoon adjoining the Northern Adriatic Sea and is the site of a commercially valuable clam (Tapes philippinarum) fishery. A three-dimensional (3D) coupled hydrodynamic–ecological model was applied to the lagoon with the objective of assessing impacts on clam food supply, commercial harvests and water quality of different clam rearing strategies, lagoon morphologies and flow regimes. Harvest and net growth to seeding ratios, total harvest value, clearance efficiencies and clam satiety were used to quantify the commercial success of different management strategies, while bottom dissolved oxygen concentrations were used as an indicator of ecosystem health. Increasing exchange with the Northern Adriatic Sea or increasing freshwater inputs into the lagoon improved clam food supply and increased both harvest production and ecosystem health in model simulations of the system. Results indicated that the high spatial and temporal variability of clam production and water quality responses must be considered for a holistic assessment of the outcomes of strategies in the context of ecological and production carrying capacity.

year: 2009

title: Otolith microchemistry of koi carp in the Waikato region, New Zealand: a tool for identifying recruitment locations

authors: Blair, Jennifer Marie

subjects: Cyprinus carpio

abstract: We assessed differences in the otolith microchemistry of koi carp, a colour variant of the invasive common carp Cyprinus carpio, at various locations in the Waikato region of New Zealand. Although koi carp are abundant here, little is known about where and in what habitats they breed. We investigated the feasibility of determining the natal habitats of adult koi carp (in the Waikato River, selected tributaries, and riverine lakes in the catchment) using otolith elemental signatures and employing laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Differences in elemental concentrations in water among the sites indicated that variation in otolith microchemistry was likely. Ratios of manganese (Mn), rubidium (Rb), strontium (Sr), and barium (Ba) to calcium (Ca) in otolith edges differed significantly among the sites, and Sr:Ca in the water and otoliths was positively correlated. A discriminant function analysis using Rb, Sr, and Ba accurately classified the otolith edge signatures of koi carp from some locations, but the otolith signatures of koi carp caught from adjacent locations were often indistinguishable. This suggests that our results could have been confounded by either (1) recent movement of koi carp or (2) a lack of differences in water chemistry among sites. Taken together, these results demonstrate that otolith microchemistry can be used to test retrospectively for koi carp migration between sites on a broad scale in the Waikato region, but fine-scale movements may not be detectable.

text: Otolith microchemistry of koi carp in the Waikato region, New Zealand: a tool for identifying recruitment locations We assessed differences in the otolith microchemistry of koi carp, a colour variant of the invasive common carp Cyprinus carpio, at various locations in the Waikato region of New Zealand. Although koi carp are abundant here, little is known about where and in what habitats they breed. We investigated the feasibility of determining the natal habitats of adult koi carp (in the Waikato River, selected tributaries, and riverine lakes in the catchment) using otolith elemental signatures and employing laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Differences in elemental concentrations in water among the sites indicated that variation in otolith microchemistry was likely. Ratios of manganese (Mn), rubidium (Rb), strontium (Sr), and barium (Ba) to calcium (Ca) in otolith edges differed significantly among the sites, and Sr:Ca in the water and otoliths was positively correlated. A discriminant function analysis using Rb, Sr, and Ba accurately classified the otolith edge signatures of koi carp from some locations, but the otolith signatures of koi carp caught from adjacent locations were often indistinguishable. This suggests that our results could have been confounded by either (1) recent movement of koi carp or (2) a lack of differences in water chemistry among sites. Taken together, these results demonstrate that otolith microchemistry can be used to test retrospectively for koi carp migration between sites on a broad scale in the Waikato region, but fine-scale movements may not be detectable.

year: 2012

title: Talking together: The effects of traditional Māori Pedagogy on children’s early literacy development

authors: Derby, Melissa

abstract: This article presents findings from a project that sought to determine the effects of a home-based literacy intervention on bilingual (English and Te Reo Māori) preschool children’s early literacy skills. The culturally responsive intervention, which was adapted from Tender Shoots, incorporated traditional Māori teaching and learning approaches, such as the use of storytelling, songs, games, and reminiscing about the past, as practices for supporting key cognitive skills crucial to foundational literacy, specifically phonological awareness and vocabulary knowledge. Over a 12-week period, during which the intervention was conducted, data were gathered from eight Māori preschool children and their families. The study utilised a crossover design. Four children and their families participated in the Rich Reading and Reminiscing (RRR) component of the intervention, which ran for six weeks, followed by the Strengthening Sound Sensitivity (SSS) portion of the intervention. The remaining four children completed the intervention in the reverse order of delivery. The crossover approach established a control in the study and allowed the effects of each part of the intervention on the aforementioned cognitive skills to be more clearly revealed. Overall, the data indicate that traditional Māori pedagogical practices helped to strengthen the early literacy skills of the children participating in the study.

text: Talking together: The effects of traditional Māori Pedagogy on children’s early literacy development This article presents findings from a project that sought to determine the effects of a home-based literacy intervention on bilingual (English and Te Reo Māori) preschool children’s early literacy skills. The culturally responsive intervention, which was adapted from Tender Shoots, incorporated traditional Māori teaching and learning approaches, such as the use of storytelling, songs, games, and reminiscing about the past, as practices for supporting key cognitive skills crucial to foundational literacy, specifically phonological awareness and vocabulary knowledge. Over a 12-week period, during which the intervention was conducted, data were gathered from eight Māori preschool children and their families. The study utilised a crossover design. Four children and their families participated in the Rich Reading and Reminiscing (RRR) component of the intervention, which ran for six weeks, followed by the Strengthening Sound Sensitivity (SSS) portion of the intervention. The remaining four children completed the intervention in the reverse order of delivery. The crossover approach established a control in the study and allowed the effects of each part of the intervention on the aforementioned cognitive skills to be more clearly revealed. Overall, the data indicate that traditional Māori pedagogical practices helped to strengthen the early literacy skills of the children participating in the study.

year: 2023-02