Sastav makrozoobentosa i mikroplastike u dnevno-noćnim uzorcima drifta duž potoka Vrapčak

master's thesis

• Title (english): Composition of macrozoobenthos and microplastics in day and night drift samples along the Vrapčak stream
• Author: Ines Maksimović
• Mentor: Mirela Sertić Perić (mentor)
• Mentor: Hana Fajković (mentor)
• Committee member: Mirela Sertić Perić (predsjednik povjerenstva)
• Committee member: Sven Jelaska (član povjerenstva)
• Committee member: Hana Fajković (član povjerenstva)
• Committee member: Ivan Čanjevac (član povjerenstva)
• Committee member: Mladen Maradin (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2022-02-18, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Urbanizacija, odnosno širenje gradova, sve je češća pojava. Gradovi često pridonose svjetlosnom
onečišćenju, koje remeti cirkadijane ritmove živih bića, uključujući njihove životne cikluse i migracije
te drift (nizvodno otplavljivanje) makrozoobentosa u urbanim potocima. Na makrozoobentos urbanih
potoka također može utjecati povećan unos mikroplastike u vodeni tok. Cilj ovog diplomskog rada jest
istražiti sastav: (i) makrozoobentosa i (ii) mikroplastike u uzorcima drifta sakupljenih tijekom dana i
noći na dvije postaje smještene duž urbanog potoka Vrapčak (Zagreb, Hrvatska). Dvije postaje (V1 i
V2) se razlikuju, između ostalog, i u intenzitetu osvijetljenosti noću pa je postaja V1 noću neosvijetljena,
a V2 je pod izravnim utjecajem ulične rasvjete. Uzorci drifta i vode uzimani su svaka dva tjedna, danju
i noću, tijekom travnja i svibnja 2021. godine te je ukupno sakupljeno 48 uzoraka drifta. Osim izdvajanja
i determinacije makrozoobentosa, u uzorcima drifta se provodila i analiza mikroplastike te analiza
fizikalno-kemijskih parametara u uzorcima vode. Rezultati ukazuju da umjetna rasvjeta utječe na
dnevno-noćne obrasce nekih skupina makrozoobentosa, međutim značajne razlike u ukupnoj gustoći
drifta među postajama i dobu dana nisu dokazane. Od čestica za koje se sumnjalo da su mikroplastika
(njih 47), svega dvije su sastavom odgovarale polietilenu, što ukazuje da unos mikroplastike u potok
Vrapčak nije velik, odnosno da potok vjerojatno nije pod velikim antropogenim pritiskom ovakvog tipa.
Većina fizikalno-kemijskih parametara se značajno razlikovala i između doba dana i među postajama.
Noću su na obje postaje zabilježene povišene vrijednosti alkaliniteta i koncentracija ortofosfata te
snižene vrijednosti koncentracija kisika i nitrata, temperature vode, kemijske potrošnje kisika te
osvjetljenja. Utvrđeno je kako s gustoćom drifta organizama značajno korelira samo brzina strujanja
vode, odnosno gustoća drifta smanjivala se s povećanjem brzine strujanja vode.

Abstract (english)

Urbanization, also known as urban expansion, is more widespread than in the past. Cities often
contribute to light pollution, which affects the circadian rhythms of living beings and disrupts their life
cycles and migration pathways, as well as macrozoobenthos drift in urban streams. Increased inputs of
microplastic particles to water also may affect macrozoobenthos in urban streams. The goal of this thesis
is to determine the composition of: (i) macrozoobenthos and (ii) microplastics in drift samples collected
during the day and night at two stations along the urban stream Vrapčak (Zagreb, Croatia). One of the
differences between the two stations (V1 and V2) was the light intensity during the night, as station V1
has no artificial light and V2 is directly illuminated by a street lamp. Drift samples were collected every
two weeks during the day and night in April and May 2021, resulting in a total of 48 drift samples.
Macrozoobenthos was isolated from the drift samples and determined. The remaining sediment was
analyzed for microplastic particles, while physicochemical parameters were analyzed from the water
samples. Results indicate that artificial light affects some macrozoobenthos taxa, but significant
differences in drift density between stations and diurnal patterns were not detected. Of all the particles
analyzed that looked like microplastics (47 pieces), only two were found to be polyethylene, indicating
that the input of microplastics into the Vrapčak stream is not significant. Therefore, the stream is
probably not under great anthropogenic influence of this type. Most physicochemical parameters
showed significant differences between the times of the day and between the stations. During the night,
alkalinity and orthophosphate values were elevated at both stations, while oxygen, nitrates, water
temperature, dissolved organic matter, and illumination values decreased. Drift density correlated only
with flow velocity, i.e., drift density decreased as flow velocity increased.

• Keywords: makroskopski beskralješnjaci; vodeni kukci; svjetlosno onečišćenje; drift; mikroplastika; fizikalno-kemijski parametri
• Keywords (english): macroscopic invertebrates; water insects; light pollution; drift; microplastics; physicochemical parameters
• Language: croatian
• URN:NBN: urn:nbn:hr:217:975913
• Study programme: Title: Enviromental Sciences; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra struke znanosti o okolišu (magistar/magistra struke znanosti o okolišu)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2023-02-18
• Created on: 2022-03-23 12:28:02