Sediment resuspension by wind in a shallow lake of Esteros del Iberá (Argentina): a model based on turbidimetry

A model based on empirical relationships is used to study frequency and magnitude of the sediment resuspension by wind-induced waves. The model has been developed for Laguna Galarza, a mesotrophic round-shaped shallow lake located in Esteros del Iberá wetland. Given the logistic and accessibility difficulties of this macrosystem, the installation of automated field stations facilitated continuous data acquisition. Using the wave theory, a daily spatial model of resuspension was built from simultaneous time series of hourly measurements of infrared nephelometric turbidity, wind speed and wind direction. The model was used to predict total suspended solids in another lake of the wetland (Laguna Iberá) showing a good agreement with observed field values, even although Laguna Iberá has a more irregular contour and a eutrophic state. Finally, we apply the model to discuss the ecological impacts of resuspension on the distribution of the littoral communities and to characterize the composition of the particulate suspended matter of the limnetic ecosystem. The model was useful to simulate the possible implications of the recent alterations of the wetland water level on the resuspension regime of the open water bodies.     

Aspects of the ecology and growth of an intertidal juvenile population of Concholepas concholepas (Mollusca: Gastropoda: Muricidae) at Las Cruces,Chile

The habitat, density and growth rate for an intertidal population of Concholepas concholepas (Bruguière, 1789) were studied at Las Cruces, Chile (Lat. 33°30′S; Long. 71°38′W) during 1977–1978. The growth rate (3.67 mm month^-1) was determined in a newly settled group, whose average length was 11.3 mm, and whose age was estimated at 3 months. The densities found ranged between 1.1 and 107.3 “locos” m^-2. Based on these results, the time of settlement of C. concholepas was calculated; capsule deposition, maximum maturity and recruitment reported by other authors for different localities are discussed.     

Spatial distribution of the infaunal benthic communities of the Ría de Muros,north-west Spain

Benthic samples were collected at 13 stations in the Ría de Muros, north-west Spain. There are three major communities: (1) in the southern and outer part of the ría, an Amphiura filiformis—Thyone fusus community, inhabiting sandy sediments with low organic content; (2) in the middle part of the ría, and Amphiura chiajei—Maldane glebifex community, inhabiting muddy sediments that are not anoxic (sulphide not detected); (3) in Muros Bay and the inner part of the ría, a Spiochaetopterus costarum community, inhabiting anoxic sediments with high organic content. Biomass is very high (up to 46.2 g ash-free dry wt) in the first two communities. In the Spiochaetopterus costarum community, biomass and diversity are much lower, probably because of oxygen deficiency.     

A system-dynamic model on the competitive growth between Potamogeton malaianus Miq. and Spirogyra sp.

A system-dynamic model has been built to evaluate the competition between submerged macrophytes Potamogeton malaianus Miq. (PM) and filamentous green algae Spirogyra sp. (SP). The data background is based on a spring–summer and an autumn–winter experiment carried out in artificial field ponds. The experiments had the aim to acquire a knowledge base necessary to a successful restoration of submerged macrophyte vegetation in Lake Taihu, China by use of P. malaianus Miq. The model mainly focuses on variations in water volume; biomass dynamics of P. malaianus Miq., Spirogyra sp. and zoobenthos; nutrients cycling between water column, P. malaianus Miq., Spirogyra sp., zoobenthos, detritus and sediment. Sixteen state variables are included in the model: biomass of P. malaianus Miq., Spirogyra sp. and zoobenthos; nitrogen in sediments, detritus, in P. malaianus Miq., in Spirogyra sp. and zoobenthos; total dissolved nitrogen; phosphorus in sediments, detritus, in P. malaianus Miq., in Spirogyra sp. and in zoobenthos; total dissolved phosphorus, and water volume of the experiment pond. The calibration and validation of the model show a good accordance with the results of the spring–summer experiment and the autumn–winter experiment.     

Macrophyte species composition and structure along littoral region in relation to limnological variables of a tropical wetland ecosystem

The composition and structure of macrophyte communities of the littoral region of Bhindawas wetland (India) was investigated. Two hypotheses were tested: (1) if limnological variables such as water chemistry and soil parameters are important determinants of species composition and abundance and (2) what is the variance in species richness and composition within the wetland. Twenty-eight macrophyte species belonging to 17 different families were identified with relatively low species diversity and richness (H′?=?2.09; Margalef index?=?1.12). Eichhornia crassipes, attained the highest relative frequency (22.69%), followed by Salvinia natans, Paspalum paspaloides, Phragmites karka, Cynodon dactylon and Cyperus alopecuroides. The first and second axis of CCA ordination explained 38.4% and 28.5% of the total variance of species–limnological variables relationship, respectively. Water-related variables (dissolved oxygen, pH and nitrate concentration) and soil nutrient factors (soil carbon and phosphorus levels) were significantly correlated to macrophyte distribution. Sampling sites formed two distinct groups based on cluster analysis, indicating varying ecological conditions. Generally, composition and abundance of macrophytes evince highly productive nature of the lake, while dominance of invasive species like E. crassipes and S. natans indicates high influence of increased nutrient levels and anthropogenic activities in the catchment on lake macrophyte composition.     

Effects of More Frequent and Prolonged El Niño Events on Life-History Parameters of the Degu, a Long-Lived and Slow-Reproducing Rodent

Abstract:  Global climate change (GCC) can have profound effects on species whose ecology is governed primarily by climatic factors. The ecology of small mammals inhabiting semiarid Chile is strongly affected by the El Niño Southern Oscillation (ENSO). During La Niña events in this area, dry conditions prevail and species may disappear from the thorn-scrub habitat. Conversely, El Niño events bring high rainfall, and associated pulses of food trigger small-mammal population increases. We used capture–mark–recapture to study responses of the degu ( Octodon degus ), a dominant small mammal, to variation in rainfall over 18 years. In response to a recent trend toward wetter conditions, degus reached record-high densities and maintained more stable numbers in the area. Underlying mechanisms involved variation in adult survival, juvenile persistence, and fecundity linked to rainfall changes during consecutive years (i.e., rainfall phases). During prolonged droughts, degus had low survival and produced fewer offspring, with low persistence. Following high rainfall, these parameters reversed; consecutive wet years resulted in further increases. Weak declines in fecundity and adult survival and high persistence of juveniles explained delayed responses to deteriorating conditions in initial dry years. If GCC leads to increased frequency of El Niño events, we anticipate greater numerical dominance of degus in semiarid Chile and possible range expansion. Furthermore, degus have strong impacts on other small mammal and some plant species, are important prey species, and are agricultural pests and disease reservoirs. Hence, GCC has the potential to dramatically influence their ecology in northern Chile and to have cascading effects on other components of this system.     

Primary productivity and particulate organic matter flow in an estuarine mangrove-wetland in Hong Kong

Net primary productivity and organic matter flow of a mangrove-dominated wetland was estimated by following production and detritus dynamics in a tidal pond in north west Hong Kong in 1986–1988 (9.1 ha). Total productivity was 12.47 t dry wt ha^–1 yr^–1, of which >90% was from emergent macrophytes (the mangroveKandelia candel and the reedPhragmites communis). High turbidity and high summer temperatures probably limited respective production by phytoplankton and benthic macroalgae (dominated byEnteromorpha crinata). Despite the high total productivity, little detritus was exported from the emergent macrophyte stands, due to the low inundation frequency. This created a net water column carbon deficit which was provided for by the high organic matter import (mean = 4.42 g ash free dry wt m^–2 d^–1) from the incoming water. This same sediment and particulate organic carbon input giving a high accretion rate of 1.7 cm yr^–1 was probably also the force behind progressive dis-coupling of emergent macrophyte production from water column consumers. This resulted in a tendency to retain production in the emergent macrophyte stands while the water column community increasingly relied on allochthonous carbon. This shift from a net exporter to a net importer of carbon in landward wetlands is probably characteristic of the transition into nutrient-conservative terrestrial systems.     

气象水文因子对呼伦湖湿地区域植物气候生产潜力的影响

利用呼伦湖湿地50年的气象资料、水文资料和生态环境监测资料,采用迈阿密模型及回归统计分析方法,分析了气象水文因子对呼伦湖湿地区域植物气候生产潜力的影响,结果表明,①50年来该湿地植物气候生产潜力变化趋势总体为下降趋势,减少的气候倾向率为每10年157.7 kg·km-2,峰值时段为1970—1990年,两个谷值时段为1961—1969年、1991—2010年,最大值和最小值与降水量出现的最多值和最少值一一对应。②在15个气象水文因子中有年降水量、年蒸散量、生长季径流量、春季大风日数、水位、春季平均风速、年大风日数、水域面积8个因子达到显著性检验（P〈0.150～0.001）,上述8个因子的排序也是与湿地区域植物气候生产潜力相关程度由大到小的排序。综述表明,呼伦湖湿地区域呈暖干化趋势,并且干旱灾害比较严重,是限制气候生产潜力的重要原因。③气象水文因子协同作用对该湿地区域植物气候生产潜力的影响较大,复相关系数为-0.997,年蒸散量与年平均气温、年降水量、生长季径流量和水位因子对湿地区域植物气候生产潜力的贡献相反,随其减少或增加,湿地区域植物气候生产潜力变化率增加或减少149.7 kg·hm-2。可以看出,该湿地气象水文因子的匹配并不理想,暖干化趋势依然是制约该区光能利用率低下的重要原因。④该湿地区域植物现实的生产力远未达到气候生产潜力,约有近60%的潜力可以开发;光能利用率较小的主要原因：一是现有的生态保护、修复技术及管理水平还比较落后,二是该区域暖干化趋势显著;而提高气候资源利用率的有效途径是加大保护生态环境力度和积极实施人工增雨、节水灌溉工程。     

Seasonal changes of benthic megafauna in the Ría de Muros e Noia (Galicia,North-West Spain)

A community of decapod crustaceans (Brachyura) was sampled seasonally (October 1978–July 1979) from three habitats (raft, middle and beach) in the Ría de Muros e Noia (North-West Spain), with the purpose of studying spatial and temporal changes in the community and comparing with communities in the neighbouring Ría de Arousa, which supports an intense mussel (Mytilus edulis)-raft culture. The Portunidae family dominated the decapod community. Polybius henslowi, a species with pelagic stages, which enters the rías periodically in large numbers, was the dominant species at all the stations throughout the sampling period, attaining densities of 1.6 individuals m^-2 (18.7 g wet wt m^-2) in summer. Macropipus depurator and M. puber were the next most important species at the raft station, M. depurator at middle stations, and M. vernalis and Carcinus maenas at beach stations. The highest population densities were recorded in summer, due to the great abundance of Polybius henslowi at this time. When the data were reconsidered omitting p. henslowi, highest densities were in autumn and winter in the inner ría. In general, the nature of the substratum, the presence of mussel rafts, depth and salinity were the main factors determining the structure of the community. Density and biomass in the Ría de Muros e Noia (P. henslowi omitted) were lower than in the Ría de Arousa (up to six times lower in some areas). The Ría de Muros lacks the extensive number of mussel rafts present in the Ría de Arousa which constitute an important food resource for decapods.     

几种植物对潜流型湖滨湿地中氮磷的处理效果比较

湖滨带是连接湖泊水域生态系统与陆地生态系统的一个功能过渡区,是湖泊的最后一道保护屏障。在河流的入湖口建造湖滨湿地,可有效净化入湖水中携带的部分有机污染物、营养盐等。湿地净化污染物的机理极为复杂,其中植被起着重要的作用。选择适当的植物是构建湿地系统的关键。以云南省抚仙湖北岸的湖滨湿地——马料河潜流型湿地为研究对象,探讨了美人蕉(Cannaindica),菖蒲(AcoruscalamusLinn),伞竹(Cyperusalternifolius),香蒲(Typhaelatifolia)四种不同植被系统的潜流型湖滨湿地去除污水中营养盐的效果,为抚仙湖湖滨带人工湿地的合理优化选择植物提供一定的依据。结果表明,四种植被系统的潜流湿地对总氮和总磷均有一定的去除效果。但是由于湿地长期运行而疏于管理,植物没有定期收割翻新,四种植物的氮磷去除率差别不太大,去除效果均不太佳。其中,美人蕉对总氮和总磷的去除效果较好,其去除率分别是30.4%,19.13%,其次为香蒲和伞竹,效果较差的是菖蒲。并且实验表明,暴雨对四种植物湿地氮的去除效果有很大的影响。连续几天的暴雨情况下,四种植物系统氮的去除率都很低。     

Influence of mussel rafts on spatial and seasonal abundance of crabs in the Ría de Arousa,North-West Spain

The crab community in the Ría de Arousa, North-West Spain, was studied for 2 yr (1974–1975; 1975–1976), firstly to detect any differences due to mussel (Mytilus edulis) raft aquaculture; secondly to study temporal changes in spatial distributions in beach, raft and non-raft areas throughout the ría. Portunid crabs dominated the fauna, the dominant species being Macropipus puber and M. depurator in the raft areas, M. depurator in non-raft subtidal areas, and M. arcuatus in beach stations. No substantial seasonal changes were observed in species composition throughout the ría. In general, the highest densities occurred in fall and winter. Raft stations showed the highest values of abundance, up to 0.47 individual per m², and 8.20 g wet wt m^-2. The food resource provided by the rich epifauna associated with the mussel rafts, and changes in the sediment due to shell deposits could account for the high density values in raft areas. Raft areas (polygons) cover about 10% of the surface of the Ría de Arousa and, thus, the raft aquaculture of mussels significantly increases crab production.     

Living in the front: Neomysis americana (Mysidacea) in the Río de la Plata estuary, Argentina-Uruguay

The Río de la Plata is one of the main estuarine systems of South America. It is characterized by a salt wedge regime, a well-developed bottom salinity front, and a maximum turbidity zone associated with it. We described, for the first time, the spatial distributional patterns of Neomysis americana, the most abundant mysid and the main food item for juvenile fishes in this estuary. We analyzed the link between mysid distribution and abundance and the bottom salinity gradient. A total of 242 plankton samples were taken from the Río de la Plata estuary in spring and fall between 1991 and 2001. Bottom salinity gradient was quantified from grids created on the basis of 348 oceanographic stations. The N. americana population was characterized by high abundances (up to 2500 ind. m⁻³), with juveniles, males, gravid and non-gravid females present in both spring and fall of different years. N. americana distribution followed the position of the bottom salinity front in different years and seasons. Pearson’s correlation analysis between mysid abundance and bottom salinity gradient confirmed the association of mysids with the bottom salinity front (maximum salinity gradient). No correlation was detected between mysid abundance and salinity per se or temperature (neither in spring nor in fall). We speculate that mysids concentrated at the front could take advantage of the high concentration of detrital material for feeding. The results of our work highlight the importance of the magnitude of salinity gradient for the ecological processes of a salt-wedge estuary like the Río de la Plata. The analysis of the spatial distribution of gradient values presented in this work also constitutes a useful tool to locate key ecological areas such as fronts.     

Marsh macrophyte responses to inundation anticipate impacts of sea-level rise and indicate ongoing drowning of North Carolina marshes

In situ persistence of coastal marsh habitat as sea level rises depends on whether macrophytes induce compensatory accretion of the marsh surface. Experimental planters in two North Carolina marshes served to expose two dominant macrophyte species to six different elevations spanning 0.75 m (inundation durations 0.4–99 %). Spartina alterniflora and Juncus roemerianus exhibited similar responses—with production in planters suggesting initial increases and then demonstrating subsequent steep declines with increasing inundation, conforming to a segment of the ecophysiological parabola. Projecting inundation levels experienced by macrophytes in the planters onto adjacent marsh platforms revealed that neither species occupied elevations associated with increasing production. Declining macrophyte production with rising seas reduces both bioaccumulation of roots below-ground and baffle-induced sedimentation above-ground. By occupying only descending portions of the parabola, macrophytes in central North Carolina marshes are responding to rising water levels by progressive declines in production, ultimately leading to marsh drowning.     

Sea level rise and eelgrass (Zostera marina) production: A spatially explicit relative elevation model for Padilla Bay, WA

The dynamics that govern the elevation of a coastal wetland relative to sea level are complex, involving non-linear feedbacks among opposing processes. Changes in the balance between these processes can result in significant alterations to vegetation communities that are adapted to a specific range of water levels. Given that current sedimentation rates in Padilla Bay, Washington are likely less than historical levels and that eustatic sea level rise is accelerating, the extensive Zostera marina (eelgrass) meadows in the bay may be at risk of eventual submergence. We developed a spatially explicit relative elevation model and used it to project changes in the productivity and distribution of eelgrass in Padilla Bay over the next century. The model is mechanistic and incorporates many of the processes and feedbacks that govern coastal wetland elevation change. Accretion estimates made using ²¹⁰Pb dating of sediment cores, sediment characteristics measured within cores, and eelgrass productivity and decomposition data were used to initialize and calibrate the model. Validation was performed using an elevation change rate measured with a network of surface elevation tables. Both the field data and model simulations revealed a net accretion deficit for the bay. Simulations using current rates of sea level rise indicated an overall expansion of eelgrass within Padilla Bay over the next century as it migrates from the center of the bay shoreward.     

Individual-based modeling of flooding and salinity effects on a coastal swamp forest

Coastal swamps are among the rapidly vanishing wetland habitats in Louisiana. Increased flooding, nutrient and sediment deprivation, and salt-water intrusion have been implicated as probable causes of the decline of coastal swamps. We developed a two-species individual-based forest succession model to compare the growth and composition of a cypress-tupelo swamp under various combinations of flooding intensity and salinity levels, using historical time-series of stage and salinity data as inputs. Our model simulates forest succession over 500 years by representing the growth, mortality, and reproduction of individual Taxodium distichum (baldcypress) and Nyssa aquatica (water tupelo) trees in a 1-km² spatial grid of 10 m × 10 m cells that vary in water levels and salinity through differences in elevation. We independently adjusted the elevations of each cell to obtain different grid-wide mean elevations and standard deviations of elevation; this affected the temporal and spatial pattern of flooding. We calibrated the model by adjusting selected parameters until averaged basal area, stem density and wood production rates under two different mean elevations (partially versus highly flooded) were qualitatively similar to comparable values reported for swamps in the literature. Corroboration involved comparing model predictions to four well-monitored contrasting habitat sites within the Maurepas Basin, Louisiana, USA. Model predictions of both species combined showed the same patterns among sites as the data, but the model overestimated wood production and the dominance of T. distichum. Exploratory simulations predicted that increased flooding leads to swamps with reduced basal areas and stem densities, while increased salinity resulted in lower basal areas at low salinity concentration (∼1-3 psu) and complete tree mortality at higher salinity concentrations (∼2-6 psu). Our model can provide insight into the succession dynamics of coastal swamps and information for the effective design of restoration actions.     

Sexual reproduction of three coral species from the Mexican South Pacific

Our understanding of the reproductive biology of corals from the Mexican southeastern Pacific is limited, and consequently, the role of reproduction in structuring coral communities is unclear. As a first attempt to understand the importance of sexual reproduction in structuring and maintaining of the coral communities from this region, we documented the reproductive cycles over 2 years (2003–2004) in three main reef-building corals species in the region. Pocillopora damicornis was shown to be hermaphroditic with asynchronous gamete development observed only in 2004; P. gigantea was characterized as both gonochoric and cosexually hermaphroditic. Absence of mature gametes was documented in both species, and an observation may be attributed to the 2003 El Niño Southern Oscillation event, which may have inhibited reproductive maturation via thermal stress. Porites panamensis was gonochoric with asynchronous development, and planulae were generally brooded. The presence of mature gametes and planulae in P. panamensis polyps suggests that this species is an important contributor to local and, likely, regional recruitment of this species. Further research should seek to identify important source populations for these coral recruits and document the exchange of larvae between coral populations of the Mexican Pacific.     

Modelling habitat overlap among sympatric mesocarnivores in southern Illinois,USA

Few researchers have developed large-scale habitat models for sympatric carnivore species. We created habitat models for red foxes (Vulpes vulpes), coyotes (Canis latrans) and bobcats (Lynx rufus) in southern Illinois, USA, using the Penrose distance statistic, remotely sensed landscape data, and sighting location data within a GIS. Our objectives were to quantify and spatially model potential habitat differences among species. Habitat variables were quantified for 1-km² buffered areas around mesocarnivore sighting locations. Following variable reduction procedures, five habitat variables (percentage of grassland patches, interspersion–juxtaposition of forest patches, mean fractal dimension of wetland patches and the landscape, and road density) were used for analysis. Only one variable differed (P < 0.05) between red fox and coyote sighting areas (road density) and bobcat and coyote sighting areas (mean fractal dimension of the landscape). However, all five variables differed between red fox and bobcat sighting areas, indicating considerable differences in habitat affiliation between this pair-group. Compared to bobcats, red fox sightings were affiliated with more grassland cover and larger grassland patches, higher road densities, lower interspersion and juxtaposition of forest patches, and lower mean fractal dimension of wetland patches. These differences can be explained by different life history requirements relative to specific cover types. We then used the Penrose distance statistic to create habitat models for red foxes and bobcats, respectively, based on the five-variable dataset. An independent set of sighting locations were used to validate these models; model fit was good with 65% of mesocarnivore locations within the top 50% of Penrose distance values. In general, red foxes were affiliated with mixtures of agricultural and grassland cover, whereas bobcats were associated with a combination of grassland, wetland, and forest cover. The greatest habitat overlap between red foxes and bobcats was found at the interface between forested areas and more open cover types. Our study provides insight into habitat overlap among sympatric mesocarnivores, and the distance-based modelling approach we used has numerous applications for modelling wildlife–habitat relationships over large scales.     

Variation and persistence of the middle rocky intertidal community of central Chile,with and without human harvesting

Humans are an important intertidal predator in central Chile. Following a five-year study we report on the effects of the exclusion of humans from the rocky intertidal at Las Cruces, central Chile. The middle intertidal of harvested and non-harvested areas diverged in species diversity and composition during the experiment. In harvested areas the middle intertidal rocky shore was dominated throughout the study by a monoculture of mussels, Perumytilus purpuratus. When humans were excluded, the middle intertidal community switched to one dominated by barnacles (predominantly Jehlius cirratus and Chthamalus scabrosus); this community has persisted for at least three years, despite the presence of forces e.g. mussel larvae, that have the potential to alter the community structure. Such changes were mediated by the muricid gastropod Concholepas concholepas, a key-stone predator. As a consequence of the above changes, the species diversity, H', (primary space occupiers) in the non-harvested area increased from H'=0 at the beginning of the study in 1983 (when the middle intertidal community was dominated by mussels), to values ca H'=2 toward the middle of the study in 1984 (which coincided with the maximum predatory impact of C. concholepas) and subsequently decreasing to ca H'=0.5 at the end of the study in 1987 (when the middle intertida community was dominated by barnacles).Please address all correspondence to J. C. Castilla, Department of Zoology, University of Washington, Seattle, Washington 98195, USA, until March 1990     

The effects of littoral zone vegetation on turbulent mixing in lakes

Micro-scale thermal profile data were acquired in four lakes in northwest England and southeast Australia that ranged from a small, sheltered pond with a surface area of about 1 ha to more open lakes with surface areas of several square kilometres. These lakes provided a range of topographic and climatic contexts, basin morphologies and dominant macrophyte species. The data were acquired using two SCAMP profilers, one deployed in the open water and the other mounted on a field traverse deployed within the vegetated littoral zone. From these profile data, turbulence parameters were calculated. The results show the variation in the influence of vegetation on turbulence in the four lakes, which depends on the combination of wind stress, solar radiative forcing and macrophyte mechanical properties. In the sheltered pond, the vegetation alters the light climate within the water, thus reducing stratification and allowing weak, thermally-driven mixing. In the larger lakes, however, the primary action of the vegetation is to prevent surface-generated TKE from penetrating the water column, although this effect becomes less important as the plant separation increases. A simple mechanistic model, calibrated against the field data, suggests that the macrophyte mechanical properties are most important in determining the turbulent kinetic energy (TKE) profile. Increasing the number of turbulence-generating plants reduces the transport of surface-generated TKE into the deeper water, consistent with the field observations. The model suggests that solar forcing, as measured by the temperature gradient between the surface and bottom waters, is of less importance since the TKE profile is similar in runs with different gradients. Perhaps most surprisingly, the value of the surface-wind stress used in the model is not important, within the limitations of the model, as it does not change the TKE profile, except in a thin surface layer.     

Recovery of Durvillaea antarctica (Durvilleales) inside and outside Las Cruces Marine Reserve, Chile.

We present the results for over two decades of monitoring on intertidal food-gatherers and the population of the low rocky shore dweller kelp Durvillaea antarctica, a short-distance disperser, inside and outside the no-take marine reserve, Estacion Costera de Investigaciones Marinas (ECIM), at Las Cruces, central Chile. It was hypothesized that protection of an initially extremely depleted population would recover by recolonizing first the no-take area and then adjacent non-protected (exploited) areas. We found that recovery of D. antarctica occurred slowly inside ECIM, with increase in density and biomass, of up to three orders of magnitude as compared to an adjacent non-protected area, which showed approximately 2-yr delay. These results suggest that the kelp population inside ECIM was likely regulated via intraspecific competition, which did not occur outside. Results showed no evidence for juvenile vs. adult density dependence other than a weak relationship for the central area of ECIM. These findings also suggest that the population recovery and cross-boundary seeding subsides affected the population dynamics. Understanding these dynamics may enhance management and conservation policies. Our work highlights the critical value of baseline and long-term comparative studies in marine no-take protected and non-protected areas for understanding how population processes respond to human and conservation practices.