Polar microbioerosion patterns exemplified in Arctic and Antarctic barnacles
Bibliographic record
Abstract
Bioerosion is the degradation of hard substrates by living organisms, primarily in marine environments. The process is an important component of the carbon cycle, it attributes to biosedimentary processes, and it gains attention as the “other ocean acidification problem” acknowledging the acceleration of bioerosion as a consequence of the global climate change. Bioerosion leaves traces in the substrate, which serve as a useful tool to investigate palaeobathymetry or -temperature. Most bioerosion studies were conducted at low latitudes, with a focus on shallow water depths. Few studies were performed in the cold-temperate regions, but almost none at the highest latitudes in the polar seas, thus setting the scene for this doctoral thesis exploring traces of microbial bioerosion in the polar realm. Acorn barnacles from three polar study sites, spanning a wide bathymetrical range, were used as a hard substrate to visualize the microbioerosion traces in their shells by means of scanning electron microscopy of epoxy resin casts. Samples from the Arctic Svalbard archipelago were from the photic intertidal to aphotic water depths of 125 m; from the Frobisher Bay, Canadian Arctic, barnacles from 62 to 94 m were examined; from the Ross Sea, Antarctica, samples originated from 37 m to 1680 m. Each study area was investigated by semi-quantifying and statistically evaluating the ichnodiversity regarding a bathymetric trend and latitudinal gradient. In total, 29 different microendolithic traces formed by cyanobacteria (4), chlorophytes (2), rhodophytes (1), sponges (1), fungi (12), foraminifera (3), bacteria (1), unknown microorganisms (4), and cirripeds (1, macroboring) were recorded in more than 200 samples. Three traces were identified at all three sites, eight traces were found exclusively in Svalbard, one in Frobisher Bay, eight in the Ross Sea, and three were restricted to the Arctic. The inferred trace-makers were mainly organotrophs and expectedly dominated by fungi, as they are very robust and thrive even under harsh environmental conditions. The polar regions are characterized by extreme conditions such as cold temperatures, months of sea ice cover and the cycle of polar day and night. Especially the latter is reflected in a general impoverishment in phototrophic bioeroders, as statistically confirmed in Svalbard. The Svalbard study material enabled the identification and establishment of a previously unknown bioerosion trace that is interpreted as a potential key ichnotaxon for cool- to cold-water (palaeo)environments. Comparisons with studies from lower latitudes led to the conclusion that the ichnodiversity in aphotic water depths is nearly constant across all latitudes. A parallel comparison of all photic zones could not be accomplished due to scarcity of suitable samples from shallow waters caused by the sea-ice abrasion of barnacles and their comparatively limited distribution in shallow water depths in polar environments. The three comprehensive microbioerosion studies are an important step towards a better understanding of polar microbioerosion patterns and allow comparisons with lower latitudes and preliminary findings in a global context. Profound knowledge of bioerosion in polar environments is particularly important considering that the environment in the polar realm is responding to global climate change at an unprecedented pace.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".