Trophic relationships and food webs of the benthic invertebrate fauna of two aseasonal tropical streams on Bougainville Island, Papua New Guinea

ABSTRACTThe trophic ecology of Konaino Creek, a small mountain headwater stream draining rainforest in the aseasonal tropics on Bougainville Island, Papua New Guinea, was examined and a food web was constructed. The major source of energy in Konaiano Creek was allochthonous detritus, most of which had been terrestrially degraded to fine particulate organic matter rather than entering the stream as leaf litter. This fine detritus was collected by the filter-feeders (mostly Simuliidae and also Hydropsychidae) which formed the dominant functional feeding group (64.4% of the fauna). Thus filterers processed most of the allochthonous detritus and made the energy available to other trophic levels, rather than shredders (1.7% of the fauna) which perform this role in temperate headwater streams. Collector-gatherers made up 22.7% of the fauna, carnivorses, mostly Odonata, Decapoda (crabs) and Hydrobiosidae, comprised 2.8% of the fauna and grazer-scrapers made up 7.4%. The latter were inhibited by low instream production owing to heavy shading and the instability and abrasion of the substrate due to frequent spates. In comparison, the trophic ecology of the nearby, coastal, Bovo River (with a catchment mainly in rainforest but mostly cleared with introduced species at the study site) was quite different and it was dominated by collector-gatherers (74%) and grazer-scrapers (15%).

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Benthic invertebrate fauna of an aseasonal tropical mountain stream on Bougainville Island, Papua New Guinea

Marine and Freshwater Research ◽

10.1071/mf9950507 ◽

1995 ◽

Vol 46 (2) ◽

pp. 507 ◽

Cited By ~ 13

Author(s):

CM Yule

Keyword(s):

Papua New Guinea ◽

New Guinea ◽

Benthic Invertebrate ◽

Mountain Streams ◽

Mountain Stream ◽

High Mountain ◽

Invertebrate Fauna ◽

Closely Related Species ◽

Lowland Rivers ◽

Tropical Mountain

The benthic invertebrate fauna of Konaiano Creek, a small aseasonal mountain rainforest stream on Bougainville Island, Papua New Guinea, was studied over a period of 22 months. Konaiano Creek supported a diverse, mostly undescribed, fauna dominated by two closely related species of Simuliidae (55% of the total specimens collected) and two species of Hydropsychidae. Over 182 taxa were recorded, more than half of which were Diptera. Species richness in Konaiano Creek was quite high in comparison with that of similar streams in both tropical and temperate regions. There were 31 species of Trichoptera, but there were no Plecoptera, Mollusca, Psephenidae, or Megaloptera. Although many groups of marine origin such as Gastropoda, Atyidae, Palaemonidae and fish inhabited nearby coastal rivers, these animals were apparently unable to colonize high mountain streams because of the torrential, barren nature of the mid-mountain streams that sharply divide the headwater streams from the lowland rivers on Bougainville Island.

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Trophic ecology of a tropical aquatic and terrestrial food web: insights from stable isotopes (15N)

Journal of Tropical Ecology ◽

10.1017/s0266467406003336 ◽

2006 ◽

Vol 22 (4) ◽

pp. 469-476 ◽

Cited By ~ 32

Author(s):

Alexander Kupfer ◽

Reinhard Langel ◽

Stefan Scheu ◽

Werner Himstedt ◽

Mark Maraun

Keyword(s):

Food Web ◽

Trophic Ecology ◽

Isotope Analysis ◽

Trophic Levels ◽

Trophic Relationships ◽

Isotopic Signatures ◽

Top Predators ◽

Aquatic Vertebrates ◽

Aquatic Food ◽

Litter Invertebrates

We used stable isotope analysis (15N/14N) to characterize the trophic relationships of consumer communities of an aquatic food web (a permanent pond) and the adjacent terrestrial food web (secondary dry dipterocarp forest) from a seasonal tropical field site in north-eastern Thailand. In general, isotopic signatures of aquatic vertebrates were higher (δ15N range = 4.51–9.90‰) than those of invertebrates (δ15N range = 1.10–6.00‰). High 15N signatures identified water snakes and swamp eels as top predators in the pond food web. In the terrestrial food web 15N signatures of saprophagous litter invertebrates (diplopods, earthworms), termites, ants and beetle larvae were lower than in those of predatory invertebrates (scolopendrids, scorpions, whip spiders). Predatory terrestrial frogs and caecilians had lower 15N signatures than snakes, indicating that snakes are among the top predators in the terrestrial web. Based on the distribution of isotopic signatures, we estimated five trophic levels for both the aquatic and terrestrial food web. The food chains of a seasonal tropical site studied were rather short, which implies similarities to the structure of temperate food webs.

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Effects of low pH on the coral reef cryptic invertebrate communities near CO2 vents in Papua New Guinea

PLoS ONE ◽

10.1371/journal.pone.0258725 ◽

2021 ◽

Vol 16 (12) ◽

pp. e0258725

Author(s):

Laetitia Plaisance ◽

Kenan Matterson ◽

Katharina Fabricius ◽

Sergei Drovetski ◽

Chris Meyer ◽

...

Keyword(s):

Papua New Guinea ◽

New Guinea ◽

Model Systems ◽

Trophic Relationships ◽

Complex Interactions ◽

Close Proximity ◽

Low Diversity ◽

Ph Conditions ◽

Reef Fauna

Small cryptic invertebrates (the cryptofauna) are extremely abundant, ecologically important, and species rich on coral reefs. Ongoing ocean acidification is likely to have both direct effects on the biology of these organisms, as well as indirect effects through cascading impacts on their habitats and trophic relationships. Naturally acidified habitats have been important model systems for studying these complex interactions because entire communities that are adapted to these environmental conditions can be analyzed. However, few studies have examined the cryptofauna because they are difficult to census quantitatively in topographically complex habitats and are challenging to identify. We addressed these challenges by using Autonomous Reef Monitoring Structures (ARMS) for sampling reef-dwelling invertebrates >2 mm in size and by using DNA barcoding for taxonomic identifications. The study took place in Papua New Guinea at two reef localities, each with three sites at varying distances from carbon dioxide seeps, thereby sampling across a natural gradient in acidification. We observed sharp overall declines in both the abundance (34–56%) and diversity (42–45%) of organisms in ARMS under the lowest pH conditions sampled (7.64–7.75). However, the overall abundance of gastropods increased slightly in lower pH conditions, and crustacean and gastropod families exhibited varying patterns. There was also variability in response between the two localities, despite their close proximity, as one control pH site displayed unusually low diversity and abundances for all invertebrate groups. The data illustrate the complexity of responses of the reef fauna to pH conditions, and the role of additional factors that influence the diversity and abundance of cryptic reef invertebrates.

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Trophic ecology of the mid-slope demersal fish community off southern Tasmania, Australia

Marine and Freshwater Research ◽

10.1071/mf01057 ◽

2002 ◽

Vol 53 (1) ◽

pp. 59 ◽

Cited By ~ 35

Author(s):

C. M. Bulman ◽

X. He ◽

J. A. Koslow

Keyword(s):

Fish Community ◽

Trophic Ecology ◽

Diet Breadth ◽

Demersal Fish ◽

Benthic Invertebrate ◽

Trophic Levels ◽

Trophic Guilds ◽

Orange Roughy ◽

Eastern Australia ◽

Australasian Region

The demersal fish community on the mid-slope off southern Tasmania in south-eastern Australia is dominated by orange roughy Hoplostethus atlanticus (Trachichthyidae), several species of oreosomatids, macrourids, squalids, alepocephalids and a synaphobranchid eel. Cluster analysis based on diet dissimilarities of proportional prey weight identified five major trophic guilds: pyrosome-feeders, crustacean feeders, piscivores, benthopelagic omnivores and benthic-invertebrate feeders. Overall, the fish fed predominantly on pelagic or benthopelagic prey, consistent with other trophic studies in the Australasian region and the Northern Hemisphere. H. atlanticus, warty dory Allocyttus verrucosus, and the macrourid Coryphaenoides serrulatus were benthopelagic omnivores that ate mesopelagic fishes, crustaceans and squid. The first two species ate more mesopelagic fishes as their sizes increased. The squalids were predominantly piscivorous but might also scavenge. Macrourids were benthic-invertebrate feeders, pelagic crustacean feeders or benthopelagic omnivores. The alepocephalids and the smooth oreo Pseudocyttus maculatus were pyrosome-feeders. No seasonal variation in diet was found for any species. Ecological indices varied within each guild. Benthopelagic omnivores and piscivores had the largest diet breadth, evenness and diversity. Trophic levels ranged from 3.0 for pyrosome-feeders to 4.9 for piscivores and the overall average for the community was 3.7.

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Stable isotopes, beaks and predators: a new tool to study the trophic ecology of cephalopods, including giant and colossal squids

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2005.3115 ◽

2005 ◽

Vol 272 (1572) ◽

pp. 1601-1607 ◽

Cited By ~ 110

Author(s):

Yves Cherel ◽

Keith A Hobson

Keyword(s):

Marine Environment ◽

Trophic Ecology ◽

Feeding Habits ◽

Progressive Increase ◽

Isotopic Signature ◽

Trophic Levels ◽

Trophic Relationships ◽

Dietary Shift ◽

Giant Squid ◽

Stable Isotopic

Cephalopods play a key role in the marine environment but knowledge of their feeding habits is limited by lack of data. Here, we have developed a new tool to investigate their feeding ecology by combining the use of their predators as biological samplers together with measurements of the stable isotopic signature of their beaks. Cephalopod beaks are chitinous hard structures that resist digestion and the stable isotope ratios of carbon (δ 13 C) and nitrogen (δ 15 N) are indicators of the foraging areas and trophic levels of consumers, respectively. First, a comparison of δ 13 C and δ 15 N values of different tissues from the same individuals showed that beaks were slightly enriched in 13 C but highly impoverished in 15 N compared with lipid-free muscle tissues. Second, beaks from the same species showed a progressive increase in their δ 15 N values with increasing size, which is in agreement with a dietary shift from lower to higher trophic levels during cephalopod growth. In the same way, there was an increase in the δ 15 N signature of various parts of the same lower beaks in the order rostrum, lateral walls and wings, which reflects the progressive growth and chitinization of the beaks in parallel with dietary changes. Third, we investigated the trophic structure of a cephalopod community for the first time. Values of δ 15 N indicate that cephalopods living in slope waters of the subantarctic Kerguelen Islands ( n =18 species) encompass almost three distinct trophic levels, with a continuum of two levels between crustacean- and fish-eaters and a distinct higher trophic level occupied by the colossal squid Mesonychoteuthis hamiltoni . δ 13 C values demonstrated that cephalopods grow in three different marine ecosystems, with 16 species living and developing in Kerguelen waters and two species migrating from either Antarctica ( Slosarczykovia circumantarctica ) or the subtropics (the giant squid Architeuthis dux ). The stable isotopic signature of beaks accumulated in predators' stomachs therefore revealed new trophic relationships and migration patterns and is a powerful tool to investigate the role of the poorly known cephalopods in the marine environment.

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Bioaccumulation and biomagnification of mercury in Lake Murray, Papua New Guinea

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f01-042 ◽

2001 ◽

Vol 58 (5) ◽

pp. 888-897 ◽

Cited By ~ 84

Author(s):

Karl C Bowles ◽

Simon C Apte ◽

William A Maher ◽

Matthew Kawei ◽

Ross Smith

Keyword(s):

Papua New Guinea ◽

Fish Species ◽

Total Mercury ◽

Trophic Position ◽

New Guinea ◽

Trophic Levels ◽

Piscivorous Fish ◽

Age Related ◽

Isotope Measurements ◽

Methylmercury Bioaccumulation

The bioaccumulation of mercury in the food webs incorporating the major piscivorous fish species of Lake Murray, Papua New Guinea, has been characterised. Methylmercury concentrations increased with trophic level and the proportion of total mercury present as methylmercury increased from <1% in plants to 94% in piscivorous fish. Methylmercury bioaccumulation factors (BAFs) were similar to those found in temperate environments, with a typical increase of 1 log unit between planktivore and piscivore trophic levels. The greatest bioaccumulation of methylmercury occurred between seston and the water column (log BAF of 5.36). The bioaccumulation of mercury to levels of regulatory concern by the lake's piscivores was attributable to the biomagnification power of the plankton-based food chain comprising four trophic levels (phytoplankton, zooplankton, planktivore, piscivore) rather than any elevated concentrations of mercury in waters or sediments. The methylmercury concentrations of individual piscivores were positively correlated with both trophic position, as indicated by δ15N measurements, and fish size. Stable-isotope measurements were used to identify fish species where dietary changes occurring with age significantly augmented age-related bioaccumulation of mercury.

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