Unveiling the Sources and Transfer of Mercury in Forest Bird Food Chains Using Techniques of Vivo-Nest Video Recording and Stable Isotopes

Knowledge gaps in mercury (Hg) biomagnification in forest birds, especially in the most species-rich tropical and subtropical forests, limit our understanding of the ecological risks of Hg deposition to forest birds. This study aimed to quantify Hg bioaccumulation and transfer in the food chains of forest birds in a subtropical montane forest using a bird diet recorded by video and stable Hg isotope signals of biological and environmental samples. Results show that inorganic mercury (IHg) does not biomagnify along food chains, whereas methylmercury (MeHg) has trophic magnification factors of 7.4-8.1 for the basal resource-invertebrate-bird food chain. The video observations and MeHg mass balance model suggest that Niltava (Niltava sundara) nestlings ingest 78% of their MeHg from forest floor invertebrates, while Flycatcher (Eumyias thalassinus) nestlings ingest 59% from emergent aquatic invertebrates (which fly onto the canopy) and 40% from canopy invertebrates. The diet of Niltava nestlings contains 40% more MeHg than that of Flycatcher nestlings, resulting in a 60% higher MeHg concentration in their feather. Hg isotopic model shows that atmospheric Hg0 is the main Hg source in the forest bird food chains and contributes >68% in most organisms. However, three categories of canopy invertebrates receive ∼50% Hg from atmospheric Hg2+. Overall, we highlight the ecological risk of MeHg exposure for understory insectivorous birds caused by atmospheric Hg0 deposition and methylation on the forest floor.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:58

Enthalten in:

Environmental science & technology - 58(2024), 13 vom: 02. Apr., Seite 6007-6018

Sprache:

Englisch

Beteiligte Personen:

Luo, Kang [VerfasserIn]
Yuan, Wei [VerfasserIn]
Lu, Zhiyun [VerfasserIn]
Xiong, Zichun [VerfasserIn]
Lin, Che-Jen [VerfasserIn]
Wang, Xun [VerfasserIn]
Feng, Xinbin [VerfasserIn]

Links:

Volltext

Themen:

Bird food chain
FXS1BY2PGL
Isotopes
Journal Article
Mercury
Mercury Isotopes
Mercury accumulation
Mercury isotopes
Methylmercury Compounds
Subtropical forest
Vivo-nest video recording
Water Pollutants, Chemical

Anmerkungen:

Date Completed 03.04.2024

Date Revised 03.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1021/acs.est.3c10972

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370028414