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These results suggest that diet was the main source of amino acids for the otolith organic matrix and there was no biochemical transamination during the assimilation of dietary amino acids to otoliths. The δ N value can be used as a proxy of nitrogen sources of fishes and may have potential application in ecological studies such as the detection of diet shift, migration, trophic levels and environmental changes experienced by the fish population.

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The narrow-barred Spanish mackerel Scomberomorus commerson is an economically essential species; however, few studies have investigated its demographic structure in the northwestern Pacific, which includes Taiwan’s waters. This study examined the growth parameters, age composition, mortality, and sex ratio of S. commerson catches by examining sagittal otoliths and other biological data collected in a 3-year project from June 2018 to June 2021. The transverse sections of sagittal otoliths exhibited alternating translucent and opaque zones, in annual cycles, and this observation was validated by otolith edge analysis. Opaque zones began to form in October; the growth peaked in December and lasted until March. Growth parameters were estimated for female (L∞ = 144.1 cm fork length [FL], k = 0.39 y−1, to = −0.85 y) and male (L∞ = 136.0 cm FL, k = 0.32 y−1, to = −1.49 y) specimens. The maximum recorded FL, body weight, and age were 159.0 cm, 27 kg, and 9.2 y for female and 135.0 cm, 17.8 kg, and 7.2 y for male specimens. Rapid growth was observed for both sexes, with FL reaching 66.8 ± 14.2 cm in female specimens and 70.1 ± 11.0 cm in male specimens during the first year of life. An age–length key based on the direct otolith aging and FL dataset (N = 646) was used to estimate the age composition of 3-year catches measured at landing (N = 16,133). The results verified that the S. commerson currently caught in the central Taiwan Strait are mainly young fish aged 1+ to 2+ y. The estimated fishing mortality (0.27 y−1) and exploitation rate (0.30) suggested that overfishing was not occurring in this stock. The findings of this study have helped clarify the population dynamics of the S. commerson in the Taiwan Strait, and the biological parameters reported herein can aid the management and conservation to ensure the sustainability of this species in this region.

For the Xitou area of National Taiwan University Experimental Forest, a nature conservation area in central Taiwan, our design team was tasked with developing a proposal for a wood footbridge, connecting pedestrian paths on either side of a steep torrent. Selected among various alternatives, our design consists of a stress ribbon glulam deck tensioned over two fan-shaped supports. These are themselves composed of curved glulam members and shaped like the leaves of a ginkgo tree. The pattern is prolonged in the wood lattice work of the guardrail. Combined foundations connect the bridge abutment and pier to each side, helping to balance out lateral forces. To permit the use of Japanese cedar sourced from the local forest, the glulam members are dimensioned to a relatively low allowable bending stress of 80 kgf/cm 2. Lessening their visual impact, most steel plate connectors are slotted into the glulam members. The bridge was finished in March and will be opened to the public in May. The resulting bridge is relatively high above the torrent, passing over the pedestrian path to one side. In addition to keeping the bridge clear of typhoon floods, this will let hikers experience crossing over and passing under the bridge, offering views from above and along the torrent. The paper will tell the story of how this design evolved, from early concept development to construction. The authors developed this design as part of their undergraduate course of study at the