Maximum Sizes of Some Species of Fish in the Far East State Marine Reserve, Peter the Great Bay, Sea of Japan

The results of 6-year-long observations on the size of some fish species of the Far East State Marine Reserve (Peter the Great Bay, Sea of Japan) suggest that resident fishes attain maximum size in the waters of the reserve. Compared to previously known sizes of fish, record values were found for the white-spotted greenling Hexagrammos stelleri (540 mm), the frog sculpin Myoxocephalus stelleri (490 mm), the snowy sculpin M. brandti (418 mm); the fringed blenny Chirolophis japonicus (520 mm), and some other fishes. These data confirm the opinion that the Marine Reserve waters are the reservation of the genofond of the inhabiting fish.     

Dolichopodid Biodiversity and Site Quality Assessment of Reed Marshes And Grasslands in Belgium (Diptera: Dolichopodidae)

The conservation value of grassland and reed marsh habitats in Belgium was determined on the basis of dolichopodid communities (Diptera: Dolichopodidae). Four grassland and one reed marsh sites within the 'Bourgoyen-Ossemeersen' Nature Reserve (B.O.) (Ghent) were sampled with white water traps from March 1993 until March 1994. Subsequently, these soil faunas were compared with those of reed marsh habitats in 'Het Meetjeslandse Krekengebied' (M.K.) sampled in 1990. Comparisons of species communities were carried out by means of multivariate analysis techniques. The DCA and CCA on the B.O. sites produced a clear separation between the grassland and the reed marsh communities. Light intensity and soil humidity were among the most important factors determining species distributions. The comparison between the B.O. and M.K. communities revealed that sampling sites were clustered according to their geographical location rather than to habitat type. Overall species richness and diversity was not significantly different between grasslands and reed marshes. However, conservation quality estimates of the sites using the Site Conservation Quality Index (SCQI) indicated that reed marshes comprise a considerably larger number of rare and Red Data Book species. Moreover, besides typical reed marsh-inhabiting species, reed marshes also house species with other ecological affinities sometimes in rather high abundance. As a result, reed marshes are considered highly valuable for the survival of several wetland dolichopodid species.     

Density and potential utilisation of medicinal grassland plants from Abe Bailey Nature Reserve, South Africa

The Abe Bailey Nature Reserve, South Africa has been identified as a potential community resource reserve compatible with biodiversity conservation. As part of the planning and public participation phase this study investigated the potential for sustainably harvesting medicinal plants. Medicinal plant use data on local species, parts used and harvesting techniques, in collaboration with neighbouring traditional healers were collected. A census of these plants was conducted in the reserve and frequency, density and abundance were calculated. A medicinal plant rating system for assessing conservation priorities was used to combine both social-qualitative and ecological-quantitative data. Five medicinal species suitable for high impact harvesting were identified. Thirty-four species have potential to be set up as harvesting trials to determine sustainable quotas. Thirty-one medicinal species including Boophane disticha, Dicoma anomala, Eucomis autumnalis, Hypoxis hemerocallidea, Pentanisia prunelloides and Indigofera daleoides are considered to be site-specific sensitive species and should not be harvested from the reserve. Following this research an on site nursery has been started at the reserve. A multi-pronged approach involving harvesting trials, propagation and plant rescue from developments to cope with escalating demand and dwindling natural populations needs to be implemented.     

Go with the flow: tidal import and export of larvae from semi-enclosed bays

There is a growing body of evidence that suggests the effective functioning of marine reserves is dependent on the dispersal and recruitment of larvae. Enhanced production inside reserves is predicted to lead to a net larval export and increased settlement and recruitment outside reserve boundaries. However, larval retention in bays is also well documented. Since bays are increasingly being used as reserve areas, planktonic larvae of benthic marine invertebrates were sampled from two semi-enclosed marine reserves during flood and ebb tides to determine whether these bays are acting as net exporters of larvae. Neither reserve was a net importer or exporter of species richness, larval abundance or diversity, although one reserve showed a small export of species richness during the hours of darkness. Both reserves balanced the net import of some species with a net export of others, which was generally related to adult or larval abundance, although exceptions were found in one reserve. Significant effects of light were found, with the net import or export of some species occurring exclusively during either the hours of daylight or darkness. An increased understanding of larval sink-source dynamics in bays is essential for ensuring their effective use as marine reserves to meet specific conservation needs. Guest editors: J. Davenport, G. Burnell, T. Cross, M. Emmerson, R. McAllen, R. Ramsay & E. Rogan Challenges to Marine Ecosystems     

Changes in the biochemical composition of tissues in Juvenile Sea bass during forced starvation

The effects of starvation on sea bass (Dicentrarchus labrax) fingerlings (initial average weight 9.5 g) at 19° in sea water were studied. Fish start to die on day 19. Proximate analysis shows that water content increases with starvation time whereas protein and lipid contents decrease. After an initial decline, nitrogen excretion remains stable from day 2 to day 14. Starvation resulted in a reduction of liver, muscle and digestive tract lipids, mainly the triglycerides which are significantly reduced within the first week of starvation. The influence of water temperature on these changes is discussed.     

Awareness of a conservation unit: a Brazilian case study

The range of uses of a conservation area by a nearby population was quantified by questionnaires applied to residents of Santa Helena county, Brazil. Of the 312 responses compiled, 71.2% of the residents acknowledged the presence of a conservation unit within the county limits while only 59.3% of the respondents had participated in some recreational or leisure outdoor activity within the unit. Activities cited by respondents included games (11.7%), beach visits (11.4%), cross-country walks (9.4%), and fishing (8.3%). A possible visitor fee to improve infrastructure within the area was approved by 64.9% of the interviewees. Suggested visitor fee varied from 50 cents to two dollars.     

Evaluation of phosphorus distribution and bioavailability in sediments of a subtropical wetland reserve in southeast China

The phosphorus (P) fractions and bioavailable P in the sediments from the Quanzhou Bay Estuarine Wetland Nature Reserve were investigated using chemical extraction methods for the first time to study the distribution and bioavailability of P in the reserve sediments. A hypothesis was presented suggesting that the bioavailable P in the sediments could be evaluated using the P fractions. The total phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP), non-apatite phosphorus (NAIP), and apatite phosphorus (AP) contents in the sediments were in the ranges of 303.87–761.59 mg kg⁻¹, 201.22–577.66 mg kg⁻¹, 75.83–179.16 mg kg⁻¹, 28.86–277.90 mg kg⁻¹, and 127.36–289.94 mg kg⁻¹, respectively. The water soluble phosphorus (WSP), readily desorbable phosphorus (RDP), algal available phosphorus (AAP), and NaHCO₃ extractable phosphorus (Olsen-P) contents in the sediments were in the ranges of 0.58–357.17 mg kg⁻¹, 80.77–586.75 mg kg⁻¹, 1.09–24.12 mg kg⁻¹, and 54.96–676.82 mg kg⁻¹, respectively. The correlation analysis results showed that the NAIP was the major component of the bioavailable P and that the impact of the AP on the bioavailable phosphorus may be minimal. Due to the low TP content in the sediments of the Quanzhou Bay Estuarine Wetland Nature Reserve, the potential pollution risks of P in the sediments may not be very high. The results also show that the bioavailable P concentrations in the sediments of the Quanzhou Bay Estuarine Wetland Nature Reserve could not be evaluated by measuring the P fractions and that the hypothesis was untenable.     

Floral organogenesis of Chloranthus sessilifolius, with special emphasis on the morphological nature of the androecium of Chloranthus (Chloranthaceae)

 Floral organogenesis of Chloranthus sessilifolius K. F. Wu is described. The inflorescence primordium is dome-like in the beginning and then elongates, and bract primordia initiate almost decussately. Each floral primordium, arising from the axil of a bract, soon becomes a scale-like structure, with three primordia of androecial lobes originating from its abaxial part, and the gynoecial primordium in adaxial position. As the androecial lobes become more distinct, four thecae are already in differentiation, and the gynoecial primordium appears as a shallow disc. The androecial lobes do not extend their length until the thecae approach maturity and the stigma is differentiated. The androecial lobes are united at all the stages of development, and the entire androecium falls off as a unit at the end of anthesis. Based on these results, combined with published evidence from neobotany, palaeobotany and phylogenetic studies, the morphological nature of the androecium of Chloranthus is further discussed. Our studies support the viewpoint that the androecial structure of Chloranthus may have arisen by splitting of a single stamen with 2 marginal thecae. Received May 2, 2001 Accepted December 18, 2001     

The robustness of a network of ecological networks to habitat loss

There have been considerable advances in our understanding of the tolerance of species interaction networks to sequential extinctions of plants and animals. However, communities of species exist in a mosaic of habitats, and the vulnerability of habitats to anthropogenic change varies. Here, we model the cascading effects of habitat loss, driven by plant extinctions, on the robustness of multiple animal groups. Our network is constructed from empirical observations of 11 animal groups in 12 habitats on farmland. We simulated sequential habitat removal scenarios: randomly; according to prior information; and with a genetic algorithm to identify best‐ and worst‐case permutations of habitat loss. We identified two semi‐natural habitats (waste ground and hedgerows together comprising < 5% of the total area of the farm) as disproportionately important to the integrity of the overall network. Our approach provides a new tool for network ecologists and for directing the management and restoration of multiple‐habitat sites.