Partitioning no-take marine reserve (NTMR) and benthic habitat effects on density of small and large-bodied tropical wrasses

No-take marine reserves (NTMRs) are increasingly implemented for fisheries management and biodiversity conservation. Yet, assessing NTMR effectiveness depends on partitioning the effects of NTMR protection and benthic habitat on protected species. Such partitioning is often difficult, since most studies lack well-designed sampling programs (i.e. Before-After-Control-Impact-Pair designs) spanning long-term time scales. Spanning 31 years, this study quantifies the effects of NTMR protection and changes to benthic habitat on the density of tropical wrasses (F. Labridae) at Sumilon and Apo Islands, Philippines. Five species of wrasse were studied: two species of large-bodied (40-50 cm TL) Hemigymnus that were vulnerable to fishing, and three species of small-bodied (10-25 cm TL) Thalassoma and Cirrhilabrus that were not targeted by fishing. NTMR protection had no measurable effect on wrasse density, irrespective of species or body size, over 20 (Sumilon) and 31 (Apo) years of protection. However, the density of wrasses was often affected strongly by benthic cover. Hemigymnus spp. had a positive association with hard coral cover, while Thalassoma spp. and Cirrhilabrus spp. had strong positive associations with cover of rubble and dead substratum. These associations were most apparent after environmental disturbances (typhoons, coral bleaching, crown of thorns starfish (COTS) outbreaks, use of explosives and drive nets) reduced live hard coral cover and increased cover of rubble, dead substratum and sand. Disturbances that reduced hard coral cover often reduced the density of Hemigymnus spp. and increased the density of Thalassoma spp. and Cirrhilabrus spp. rapidly (1-2 years). As hard coral recovered, density of Hemigymnus spp. often increased while density of Thalassoma spp. and Cirrhilabrus spp. often decreased, often on scales of 5-10 years. This study demonstrates that wrasse population density was influenced more by changes to benthic cover than by protection from fishing

Achievement of target gain larger than unity in an inertial fusion experiment.

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result

Prior and Present Evidence: How Prior Experience Interacts with Present Information in a Perceptual Decision Making Task

Vibrotactile discrimination tasks have been used to examine decision making processes in the presence of perceptual uncertainty, induced by barely discernible frequency differences between paired stimuli or by the presence of embedded noise. One lesser known property of such tasks is that decisions made on a single trial may be biased by information from prior trials. An example is the time-order effect whereby the presentation order of paired stimuli may introduce differences in accuracy. Subjects perform better when the first stimulus lies between the second stimulus and the global mean of all stimuli on the judged dimension ("preferred" time-orders) compared to the alternative presentation order ("nonpreferred" time-orders). This has been conceptualised as a "drift" of the first stimulus representation towards the global mean of the stimulus-set (an internal standard). We describe the influence of prior information in relation to the more traditionally studied factors of interest in a classic discrimination task.Sixty subjects performed a vibrotactile discrimination task with different levels of uncertainty parametrically induced by increasing task difficulty, aperiodic stimulus noise, and changing the task instructions whilst maintaining identical stimulus properties (the "context").The time-order effect had a greater influence on task performance than two of the explicit factors-task difficulty and noise-but not context. The influence of prior information increased with the distance of the first stimulus from the global mean, suggesting that the "drift" velocity of the first stimulus towards the global mean representation was greater for these trials.Awareness of the time-order effect and prior information in general is essential when studying perceptual decision making tasks. Implicit mechanisms may have a greater influence than the explicit factors under study. It also affords valuable insights into basic mechanisms of information accumulation, storage, sensory weighting, and processing in neural circuits

Decadal-scale effects of benthic habitat and marine reserve protection on Philippine goatfish (F: Mullidae)

Reef fish populations can be affected by both fishing and changes in benthic habitat. Yet, partitioning these effects is often difficult, usually requiring an appropriate sampling design and long-term monitoring. Here we quantify, over a 30-yr period, the effects of benthic habitat change and no-take marine reserve (NTMR) protection on the density and species richness of a lightly harvested benthic-feeding reef fish family, the Mullidae (goatfish), at four Philippine islands. Boosted regression trees demonstrated that goatfish density and species richness had strong negative associations with hard coral cover and strong positive associations with cover of dead substratum. No-take marine reserve protection had no effect on the density or species richness of goatfish over 19 and 30 yr at Sumilon and Apo islands, respectively. However, environmental disturbances (e.g., typhoons, coral bleaching) that reduced hard coral cover subsequently led to increases in goatfish numbers for periods ranging from 2 to 8 yr. After initial increases due to benthic disturbance, goatfish populations decreased during coral recovery, occurring on timescales of 10-20 yr. This long-term, "natural experiment" demonstrated that changes to benthic habitat (bottom-up control) had a far greater effect on Philippine goatfish populations than protection from fishing (a top-down effect) in NTMRs. Given the strong positive response of goatfish populations to loss of live hard coral cover, this group of fishes may be a valuable indicator species for habitat degradation on coral reefs

Long-term no-take marine reserve and benthic habitat effects on coral reef fishes

No-take marine reserves (NTMRs) are advocated as tools to enhance or maintain density and assemblage structure of coral reef fishes. These reef fish population and assemblage attributes may be affected by both NTMR protection and benthic habitat change. Before-after-control-impact-pair (BACIP) sampling designs and long-term (8-30 yr) monitoring at 4 Philippine NTMRs were used to examine the relative effects of NTMR protection and benthic habitat change on densities and assemblage structures of fishery-targeted (Lethrinidae and Lutjanidae) and non-targeted (Pomacentridae) reef fishes. Targeted fish density increased significantly in NTMRs relative to fished control sites at all reserves over time. Non-targeted fish density and hard coral cover displayed a variety of patterns of change over time (unrelated to NTMR protection), but closely mirrored each other. Targeted fish were considered potential predators of non-targeted fish. Availability of potential prey for predators had a larger influence than the effect of potential predators on prey, with both processes much weaker than effects of habitat change. Multivariate analyses of long-term temporal data indicated that 65.8% of the variance in assemblage structure of non-targeted pomacentrids was explained by benthic habitat variables (structural complexity, cover of dead substrate) whereas NTMR protection alone explained only 9.7%. In contrast, 36.2% of assemblage structure of targeted lethrinids/lutjanids was explained by duration of NTMR protection (42.2% excluding effects of typhoons at one reserve), with habitat variables alone explaining 24.7%. These results help clarify the relative effects of NTMR protection, benthic habitat change, and potential trophic interactions on reef fishes targeted and non-targeted by fishing

Off-reef planktivorous reef fishes respond positively to decadal-scale no-take marine reserve protection and negatively to benthic habitat change

The effects of no-take marine reserve (NTMR) protection and changes in benthic habitat on fusiliers (family Caesionidae) were investigated at four small Philippine offshore islands on time scales of 10-31years. Fusiliers are highly mobile, schooling, medium-sized planktivorous fish that generally feed off-reef. For these reasons, and given the small size of the NTMRs (3.6-37.5ha) in this study, it was predicted that fusilier density would be unlikely to show clear effects of NTMR protection, or to respond to changes in benthic habitat. In contrast to predictions, clear NTMR effects were observed on fusilier density at three of the four NTMRs, with durations of protection from 14 to 31years. Furthermore, the study provided strong evidence that benthic variables, specifically cover of live hard coral and dead substratum, affect the density of fusiliers. This effect of benthic habitat on density was highlighted by several major environmental disturbances that caused shifts in the benthic habitat from live hard coral to dead substratum. For two of the three most abundant species of fusiliers individually, and for all three of them combined (Pterocaesio pisang+Caesio caerulaurea+Pterocaesio digramma/tessellata), as live hard coral cover decreased, fish density decreased. It is hypothesized that these off-reef daytime feeders may have such a strong association with live hard coral cover because they use this habitat as nocturnal sleeping sites. Multivariate analyses indicated that, across all sites and times sampled, cover of live hard coral and dead substratum accounted for 38% of the variation in fish assemblage structure. These results are important as there are very few reports in the published literature of strong effects of NTMR protection or changes in benthic habitat on the density and assemblage structure of fusiliers

Physical realization of complex dynamical pattern formation in magnetic active feedback rings

We report the clean experimental realization of cubic–quintic complex Ginzburg–Landau (CQCGL) physics in a single driven, damped system. Four numerically predicted categories of complex dynamical behavior and pattern formation are identified for bright and dark solitary waves propagating around an active magnetic thin film-based feedback ring: (1) periodic breathing; (2) complex recurrence; (3) spontaneous spatial shifting; and (4) intermittency. These nontransient, long lifetime behaviors are observed in self-generated spin wave envelopes circulating within a dispersive, nonlinear yttrium iron garnet waveguide. The waveguide is operated in a ring geometry in which the net losses are directly compensated for via linear amplification on each round trip (of the order of 100 ns). These behaviors exhibit periods ranging from tens to thousands of round trip times (of the order of μ s) and are stable for 1000s of periods (of the order of ms). We present ten observations of these dynamical behaviors which span the experimentally accessible ranges of attractive cubic nonlinearity, dispersion, and external field strength that support the self-generation of backward volume spin waves in a four-wave-mixing dominant regime. Three-wave splitting is not explicitly forbidden and is treated as an additional source of nonlinear losses. All observed behaviors are robust over wide parameter regimes, making them promising for technological applications. We present ten experimental observations which span all categories of dynamical behavior previously theoretically predicted to be observable. This represents a complete experimental verification of the CQCGL equation as a model for the study of fundamental, complex nonlinear dynamics for driven, damped waves evolving in nonlinear, dispersive systems. The reported dynamical pattern formation of self-generated dark solitary waves in attractive nonlinearity without external sources or potentials, however, is entirely novel and is presented for both the periodic breather and complex recurrence behaviors

Partitioning no-take marine reserve (NTMR) and benthic habitat effects on density of small and large-bodied tropical wrasses

No-take marine reserves (NTMRs) are increasingly implemented for fisheries management and biodiversity conservation. Yet, assessing NTMR effectiveness depends on partitioning the effects of NTMR protection and benthic habitat on protected species. Such partitioning is often difficult, since most studies lack well-designed sampling programs (i.e. Before-After-Control-Impact-Pair designs) spanning long-term time scales. Spanning 31 years, this study quantifies the effects of NTMR protection and changes to benthic habitat on the density of tropical wrasses (F. Labridae) at Sumilon and Apo Islands, Philippines. Five species of wrasse were studied: two species of large-bodied (40-50 cm TL) Hemigymnus that were vulnerable to fishing, and three species of small-bodied (10-25 cm TL) Thalassoma and Cirrhilabrus that were not targeted by fishing. NTMR protection had no measurable effect on wrasse density, irrespective of species or body size, over 20 (Sumilon) and 31 (Apo) years of protection. However, the density of wrasses was often affected strongly by benthic cover. Hemigymnus spp. had a positive association with hard coral cover, while Thalassoma spp. and Cirrhilabrus spp. had strong positive associations with cover of rubble and dead substratum. These associations were most apparent after environmental disturbances (typhoons, coral bleaching, crown of thorns starfish (COTS) outbreaks, use of explosives and drive nets) reduced live hard coral cover and increased cover of rubble, dead substratum and sand. Disturbances that reduced hard coral cover often reduced the density of Hemigymnus spp. and increased the density of Thalassoma spp. and Cirrhilabrus spp. rapidly (1- 2 years). As hard coral recovered, density of Hemigymnus spp. often increased while density of Thalassoma spp. and Cirrhilabrus spp. often decreased, often on scales of 5-10 years. This study demonstrates that wrasse population density was influenced more by changes to benthic cover than by protection from fishing