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Tag: General (Climate & Environment)

  • Metal contamination varied across Tenerife intertidal sites

    Metal contamination varied across Tenerife intertidal sites

    What the study found

    The study found that metal contamination and metal accumulation in intertidal organisms varied across the three Tenerife sites, with El Médano generally showing the highest levels. The authors also report high aluminum in Micromelo undatus, Pagurus anachoretus, and Palaemon elegans, and elevated cadmium in Stramonita haemastoma.

    Why the authors say this matters

    The authors conclude that these organisms can serve as bioindicators, meaning living species used to reflect environmental conditions. They also say the new data support continuous monitoring and conservation strategies.

    What the researchers tested

    The researchers measured concentrations of aluminum, cadmium, copper, iron, lithium, nickel, lead, and zinc in eight intertidal species from three anthropogenically impacted sites on Tenerife: El Médano, Los Silos, and La Punta del Hidalgo. Metal concentrations were determined using ICP-OES, which stands for inductively coupled plasma optical emission spectroscopy.

    What worked and what didn't

    El Médano generally had the highest metal levels, followed by Los Silos, while La Punta del Hidalgo had the lowest. High aluminum levels were detected in Micromelo undatus, Pagurus anachoretus, and Palaemon elegans, and Stramonita haemastoma showed elevated cadmium.

    What to keep in mind

    The abstract does not describe sample sizes, measurement uncertainty, or statistical details beyond noting significant differences among sites. It also says this is the first metal dataset for Micromelo undatus, Pagurus anachoretus, and Stramonita haemastoma in the Canary Islands.

    • El Médano generally showed the highest metal contamination among the three sites.
    • La Punta del Hidalgo had the lowest metal levels overall.
    • Micromelo undatus, Pagurus anachoretus, and Palaemon elegans had high aluminum levels.
    • Stramonita haemastoma showed elevated cadmium concentrations.
    • The study provides the first metal data for three species in the Canary Islands.

  • Trace mineral levels varied by species in free-living herbivores

    What the study found

    The study found that liver trace element profiles differed by species in free-living large herbivores, with red deer showing comparatively higher copper and horses showing elevated iron and lead. It also found temporal declines in some elements, including iron and lead, across all species.

    Why the authors say this matters

    The authors conclude that species- and context-specific reference intervals are needed when assessing health in free-living herbivores, because the study's estimated intervals differed from livestock standards. The findings indicate that mineral surveillance can support wildlife health assessment, track long-term environmental changes, and inform management decisions in nature reserves.

    What the researchers tested

    The researchers used a long-term post-mortem monitoring system based on routine liver sampling from Heck cattle, Konik horses, and red deer in the Oostvaardersplassen nature reserve in the Netherlands. They measured trace minerals and heavy metals with inductively coupled plasma mass spectrometry, including arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, selenium, vanadium, and zinc.

    What worked and what didn't

    The monitoring system identified reference intervals and showed clear species-specific patterns in liver trace element concentrations. It also detected seasonal and age-related variation, as well as declining trends in some elements over time, including iron and lead across all species. Reference intervals estimated in the study differed from livestock standards, especially for copper and selenium.

    What to keep in mind

    The abstract does not describe detailed study limitations beyond noting that the findings come from a minimally managed, multi-species population at one reserve. The results are specific to the species, site, and monitoring system described in the study.

    • Red deer had comparatively higher copper levels.
    • Horses had elevated iron and lead levels.
    • Iron and lead declined over time across all species.
    • Seasonal and age-related variations were observed.
    • Reference intervals differed from livestock standards, especially for copper and selenium.

  • Parvilucifera infectans kills Alexandrium minutum and lowers toxin abundance

    What the study found

    The study found that the parasite Parvilucifera infectans can infect and kill the harmful alga Alexandrium minutum under different salinity conditions. It also found that parasite infection reduced the abundance of the alga's Paralytic Shellfish Poison toxins.

    Why the authors say this matters

    The authors suggest these host-parasite interactions are important because harmful algal blooms can be shaped not only by environmental conditions but also by parasitism. They also conclude that salinity may influence how the parasite and algae interact.

    What the researchers tested

    The researchers studied cultures of Alexandrium minutum infected with Parvilucifera infectans under salinities ranging from 20 PSU to 32 PSU. They monitored infection success, used microscopy, recovered cells for extraction, and profiled metabolites with ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS).

    What worked and what didn't

    Parvilucifera infectans tolerated salinity from 20 PSU to 32 PSU and killed whole algal cultures within 3 weeks in laboratory experiments. Comparative metabolomics showed that infection, rather than salinity, caused major shifts in the host cell metabolome and decreased the abundance of algal toxins. Several polar metabolites and osmolytes, including ectoine, dimethylsulfoniopropionate, glycine betaine, choline, and carnitine, were elevated in infected cells.

    What to keep in mind

    The study was done in laboratory-controlled cultures, so the findings are limited to the conditions tested. The abstract does not describe broader environmental limits or long-term ecological outcomes beyond the observed infection and metabolome changes.

    • Parvilucifera infectans infected and killed Alexandrium minutum under salinities from 20 PSU to 32 PSU.
    • Parasite infection reduced the abundance of Paralytic Shellfish Poison toxins in the alga.
    • Infection, rather than salinity, drove major shifts in the host metabolome.
    • Several osmolytes and polar metabolites were elevated in infected cells, including ectoine and glycine betaine.
    • Whole algal cultures died within 3 weeks in the laboratory experiments.