Mangrove Ecology

Natural History Note: A Novel Terrestrial Fish Habitat inside Emergent Logs

by Ben Chapman

The proteomes of Sydney rock oysters vary spatially according to exposure to acid sulfate runoff

by Valter Amaral

Amaral V, Thompson EL, Bishop MJ, Raftos DA, 2012 Mar Freshwat Res 63: 361-369. doi:10.1071/MF11213 [featured in the cover of the issue]

Runoff from acid sulfate soils (ASS) has large negative environmental and economic impacts on estuarine ecosystems.... more Runoff from acid sulfate soils (ASS) has large negative environmental and economic impacts on estuarine ecosystems. Oysters display reduced abundance, growth rate and shell thickness when exposed to ASS runoff, yet the molecular underpinnings of their responses have not been explored. We hypothesized that the proteomes of wild Sydney rock oysters, Saccostrea glomerata, would differ between populations that are recurrently exposed to and that are unaffected by runoff from ASS. We used two-dimensional electrophoresis to compare protein abundances in the gills of S. glomerata collected from two sites close to (acidified) and two sites away from (reference) major ASS outflow drains in a south-east Australian estuary. Approximately 5 % of the proteome was differentially expressed between oysters from acidified and reference sites, with 5 protein spots more abundant and one less abundant at the sites close to drains. Another protein spot was present only in oysters from reference sites. This study has provided the first screening of spatial variation in the protein expression of S. glomerata with respect to discharge from ASS. Altered protein expression may underpin short-term inducible responses to ASS runoff, or genetic resistance acquired through recurrent exposure of populations to the stressor.

Litterfall dynamics in an overcrowded mangrove Kandelia obovata (S., L.) Yong stand over five year

by Sahadev Sharma

Baeza, J.A. 2010. Sexual system and natural history observations on semi-terrestrial shrimp Merguia rhizophorae. Invertebrate Biology 129(3): 266–276.

by Antonio Baeza

Late Holocene mangrove dynamics of Marajo island in Amazonia, northern Brazil

by Marcelo Cohen

Palaeolimnological studies and ancient maps confirm secular climate fluctuations in Amazonia

by Marcelo Cohen

Past and Current Mangrove Dynamics on the Bragança Peninsula Northern Brazil

by Marcelo Cohen

Model of wetland development of the Amapá coast during the late Holocene

by Marcelo Cohen

Mid-and late-Holocene sedimentary process and palaeovegetation changes near the mouth of the Amazon River

by Marcelo Cohen

Mangrove ecosystem services and the potential for carbon revenue programmes in Solomon Islands

by Sturle Hauge Simonsen

Full reference: Warren-Rhodes, K., Schwarz, A.-M., Boyle, L., Albert, J., Suti Agalo, S., Warren, R., Bana, A., Paul, C., Kodosiku, R., Bosma, W., Yee, D., Rönnbäck, P., Crona, B., Duke, N. (2011) Mangrove ecosystem services and the potential for carbon revenue programmes in Solomon Islands. Environmental Conservation 38(4)485-496

Mangroves are an imperilled biome whose protection and restoration through payments for ecosystem services (PES) can... more Mangroves are an imperilled biome whose protection and restoration through payments for ecosystem services (PES) can contribute to improved livelihoods, climate mitigation and adaptation.

Interviews with resource users in three Solomon Islands villages suggest a strong reliance upon mangrove goods for subsistence and cash, particularly for firewood, food and building materials. Village-derived economic data indicates a minimum annual subsistence value from mangroves of US$ 345—1501 per household.

Fish and nursery habitat and storm protection were widely recognized and highly valued mangrove ecosystem services. All villagers agreed that mangroves were under threat, with firewood overharvesting considered the primary cause. Multivariate analyses revealed village affiliation and religious denomination as the most important factors determining the use and importance of mangrove goods.

These factors, together with gender, affected users´ awareness of ecosystem services. The importance placed on mangrove services did not differ significantly by village, religious denomination, gender, age, income, education or occupation.

Mangrove ecosystem surveys are useful as tools for raising community awareness and input prior to design of PES systems. Land tenure and marine property rights, and how this complexity may both complicate and facilitate potential carbon credit programmes in the Pacific, are discussed.

Moderate acidification affects growth but not survival of 6-month-old oysters

by Valter Amaral

Amaral V, Cabral HN, Bishop MJ, 2012 Aquat Ecol 46: 119-127. doi:10.1007/s10452-011-9385-5

Oyster populations periodically exposed to runoff from acid sulfate soils (ASS) are of depressed abundance and have... more Oyster populations periodically exposed to runoff from acid sulfate soils (ASS) are of depressed abundance and have fewer smaller individuals than unaffected populations, despite having similar recruitment levels to unaffected sites during dry periods. We examined how the timing and duration of exposure to ASS runoff influences the growth and survival of successfully settled oysters. We predicted that among 6-month-old oysters, growth and survival would be (1) lower among individuals continuously exposed to ASS-acidified waters than those that are episodically exposed, and (2) most negatively affected during rainfall events, which enhance transport of ASS runoff to estuaries. Six-month-old Sydney rock oysters, Saccostrea glomerata, were deployed at ASS-affected and unaffected sites within each of two south-east Australian estuaries. After 10 weeks, oysters were transplanted within and across sites in an estuary and maintained in situ for another 10 weeks. Oysters that remained for 20 weeks at ASS-affected sites grew at just over half the rate of oysters at reference sites. Oysters transplanted from acidified to reference sites grew more than oysters transplanted from reference to acidified sites or oysters that remained at reference sites. Unexpectedly, overall oyster mortality was low. Greater rainfall, and hence a lower pH, is likely to have accounted for the greater impact of acidification on growth during the second 10 weeks. Where oysters recruit to a 6-month age cohort, they may be able to tolerate subsequent, moderate, acidification events. Reduced growth during acidification periods may be offset by positive growth during intervening dry periods.

Allometric relationships for estimating the aboveground mass and leaf area of mangrove Bruguiera gymnorrhiza trees in Manko wetland, Okinawa Island, Japan

by Sahadev Sharma

Litterfall dynamics in mangrove Kandelia obovata (S. L.,) Yong stands on Okinawa Island, Japan over four year

by Sahadev Sharma

Crown Foliage Dynamics of Mangrove Kandelia obovata in Manko Wetland, Okinawa Island, Japan

by Sahadev Sharma

Seasonal variation in the size-dependent respiration of mangroves Kandelia obovata

by Sahadev Sharma

Vegetative and Reproductive Phenology, and Litterfall Production of Rhizophora stylosa in Okinawa Island, Japan

by Sahadev Sharma

Above and Belowground Carbon Acquisition of Mangrove Kandelia obovata Trees in Manko Wetland, Okinawa, Japan

by Sahadev Sharma

Paleoreconstruction of estuarine sediments reveal human‐induced weakening of coastal carbon sinks

by Peter Macreadie

Global Change Biology (2012)
18: 891-901

Human activities in coastal areas frequently cause loss of benthic macrophytes (e.g. seagrasses) and concomitant... more Human activities in coastal areas frequently cause loss of benthic macrophytes (e.g. seagrasses) and concomitant increases in microalgal production through eutrophication. Whether such changes translate into shifts in the composition of sediment detritus is largely unknown, yet such changes could impact the role these ecosystems play in sequestrating CO2. We reconstructed the sedimentary records of cores taken from two sites within Botany Bay, Sydney – the site of European settlement of Australia – to look for human-induced changes in dominant sources of detritus in this estuary. Cores covered a period from the present day back to the middle Holocene (~6,000 y) according to 210Pb profiles and radiocarbon (14C) dating. Depositional histories at both sites couldn’t be characterized by a linear sedimentation rate; sedimentation rates in the last 30-50 years were considerably higher than during the rest of the Holocene. C:N ratios declined and began to exhibit a microalgal source signature from around the time of European settlement, which could be explained by increased nutrient flows into the Bay caused by anthropogenic activity. Analysis of stable isotopic ratios of 12C/13C showed that the relative contribution of seagrass and C3 terrestrial plants (mangroves, saltmarsh) to detritus declined around the time of rapid industrial expansion (~1950’s), coinciding with an increase in the contribution of microalgal sources. We conclude that the relative contribution of microalgae to detritus has increased within Botany Bay, and that this shift is the sign of increased industrialization and concomitant eutrophication. Given the lower carbon burial efficiencies of microalgae (~0.1%) relative to seagrasses and C3 terrestrial plants (up to 10%), such changes represent a substantial weakening of the carbon sink potential of Botany Bay – this occurrence is likely to be common to human-impacted estuaries, and has consequences for the role these systems play in helping to mitigate climate change.

Multivariate characterisation of the habitats of seven species of Malayan mudskippers (Gobiidae: Oxudercinae)

by Gianluca Polgar

Crossing habitat boundaries: mechanisms underlying cross-habitat utilization by reef fishes.

by Monique Grol

Grol MGG - 2010 - PhD-thesis. ISBN/EAN 978-90-9025458-6.

This thesis contributes to a better understanding of the nursery-role hypothesis of non-reef habitats for coral reef... more This thesis contributes to a better understanding of the nursery-role hypothesis of non-reef habitats for coral reef fishes. Not only fish densities were studied in multiple habitats, but also factors which could drive ontogenetic habitat shifts by fishes, such as habitat structural complexity, food abundance, fish growth rates, predator abundance, survival from predation, fish condition and maturation. The existence of a complex, multi-stage habitat utilization pattern during the life-history of a common coral reef fish species was studied in detail, and compelling evidence is provided for the underlying mechanisms causing ontogenetic habitat shifts. An understanding of these mechanisms is of great importance and will provide a more robust foundation to work toward effective management and conservation strategies.