The combined effects of water velocity (U) and dissolved inorganic carbon (DIC) concentration on photosynthesis rates of Vallisneria americana were investigated. The net photosynthesis rate or O 2 flux (J obs ) from leaves increased with U from 0.20 6 0.01 (mean 6 standard error) mmol m 22 s 21 at U 5 0 m s 21 (i.e., in stagnant water) to 2.1 6 0. Sc 0.33 were higher than predicted for a laminar flat plate boundary layer, indicating that physicochemical activity, such as photosynthesis, influenced Sh x . The thickness of the measured concentration boundary layer (d CBL ) and the diffusive sublayer (d DSL ) were 63% and 70% smaller, respectively, than theoretical values based on hydrodynamic theory. Theoretical hydrodynamic predictions of mass transfer need to account for biological reactions.

Kelp forest ecosystems and their associated ecosystem services are declining around the world. In response, marine managers are working to restore and counteract these declines. Kelp restoration first started in the 1700s in Japan and since then has spread across the globe. Restoration efforts, however, have been largely disconnected, with varying methodologies trialled by different actors in different countries. Moreover, a small subset of these efforts are 'afforestation', which focuses on creating new kelp habitat, as opposed to restoring kelp where it previously existed. To distil lessons learned over the last 300 years of kelp restoration, we review the history of kelp restoration (including afforestation) around the world and synthesise the results of 259 documented restoration attempts spanning from 1957 to 2020, across 16 countries, five languages, and multiple user groups. Our results show that kelp restoration projects have increased in frequency, have employed 10 different methodologies and targeted 17 different kelp genera. Of these projects, the majority have been led by academics (62%), have been conducted at sizes of less than 1 ha (80%) and took place over time spans of less than 2 years. We show that projects are most successful when they are located near existing kelp forests. Further, disturbance events such as sea-urchin grazing are identified as regular causes of project failure. Costs for restoration are historically high, averaging hundreds of thousands of dollars per hectare, therefore we explore avenues to reduce these costs and suggest financial and legal pathways for scaling up future restoration efforts. One key suggestion is the creation of a living database which serves as a platform for recording restoration projects, showcasing and/or

Environmental changes influence foraging behavior for most animals. Dolphinfish, Coryphaena hippurus, are epipelagic predators and have a cosmopolitan tropical to warm-temperate (>20°C) distribution. We simultaneously obtained the ambient temperature and the foraging behavior (i.e., swimming speed, depth and tailbeat acceleration) of dolphinfish, using an acceleration data-individuals. Although the dolphinfish spent a mean ± standard deviation of 43.4±27.7% of their time at the surface (0-5 m), dive excursions from the surface (DES) were observed in all individuals and maximum DES depths ranged from 50.1 to 95.4 m. DES events resulted dives below the thermocline for these dolphinfish, and there was a significantly positive relationship between the isothermal layer depth (ILD) and DES depth. Our results demonstrate that dolphinfish avoided the rapid thermal change beyond the thermocline, and their prey is most likely found in the upper layers of the thermocline. Gliding behavior during the DES phase was also observed and dolphinfish gradually descended to deeper waters with gliding. The gliding time was longer when the ILD was deeper, and fish tended to dive deeper. We suggest that dolphinfish adopt gliding behavior to search a broader range of depths for prey, while minimizing energy use.

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Ocean acidification, due to diffusive uptake of atmospheric CO 2 , has potentially profound ramifications for the entire marine ecosystem. Scientific knowledge on the biological impacts of ocean acidification is rapidly accumulating; however, data are still scarce on whether and how ocean acidification affects the reproductive system of marine organisms. We evaluated the long-term (9 mo) effects of high CO 2 (1000 µatm) on the gametogenesis, survival, growth and physiology of the sea urchin Hemicentrotus pulcherrimus. Hypercapnic exposure delayed gonad maturation and spawning by 1 mo, whereas it had no effect on the maximum number of ova, survival or growth. After 9 mo of exposure, pH (control: 7.61, high-CO 2 : 7.03) and Mg 2+ concentration (control: 50.3, high-CO 2 : 48.6 mmol l −1 ) of the coelomic fluid were significantly lower in the experimental urchins. In addition, a 16 d exposure experiment revealed that 1000 µatm CO 2 suppressed food intake to < 30% of that of the controls. These data suggest that the ocean condition predicted to occur by the end of this century disrupts the physiological status of the sea urchin, possibly through reduced energy intake, which may delay reproductive phenology of the species. Taking into account earlier studies reporting negative impacts of ocean acidification on the early development of the same species, these results imply that ocean acidification will threaten H. pulcherrimus at a community level. KEY WORDS: CO 2 · Ocean acidification · Sea urchin · Reproduction · Feeding · PhysiologyResale or republication not permitted without written consent of the publisher Aquat Biol 18: 281-292, 2013 the biological process by affecting the energy balance of the organism. The energy budget of living organisms follows the 'law of conservation of energy', and the energy input (food source) is equal to the energy output, which is divided between growth (production of tissue), reproduction (production of gametes), maintenance metabolism and excretory loss (Sibly & Calow 1986). Under low energy input or stress conditions, this allocation is suggested to follow the principles of maximizing fitness, and studies have shown that allocation to maintenance tends to take precedence over growth or reproduction (Zera & Harshman 2001, Schneider 2004, Koojiman 2010, Sokolova et al. 2012. Recent studies have indicated that an acidified environment involves potential energy costs for metabolic adaptations and calcification (Melzner et al. 2009, Lannig et al. 2010, Sokolova et al. 2012, thus one might expect that reallocation of energy between somatic and gonad growth will occur in acidified conditions. However, though there are several studies evaluating the effect of ocean acidification on growth rate, to our knowledge, there is a limited number of studies that have examined the effect of high CO 2 on the reproductive potential of marine organisms. Wood et al. (2008) reported that egg size was not affected in regenerating arms of ophiuroid Amphiura filiformis cultured in seawater pH ...

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