Ascidians and sponges… here we go!

The journey to understand the diversity and potential negative impacts of ascidians and sponges in Kimbe Bay has just started. Our crew is an amalgam of people from many cultural backgrounds but working efficiently as a team and sharing a common goal: exploring groups of organisms that are usually neglected and unveil how do they influence coral systems and reef associated fishes.

Nuestra aventura para conocer la diversidad y los imapctos negativos potenciales de las ascidias y esponjas en Kimbe acaba de comenzar. Nuestro grupo es una amalgama de gente de diferentes orígenes culturales pero que trabaja eficientemente como equipo y comparte un objetivo común: explorar grupos de organismos que usualmente son ignorados y entender como ellos pueden influenciar los arrecifes de coral y los peces asociados a arrecifes.

The team

Research team at Kimbe Bay, left to right: Nelson Sikatua, Saul González Murcia, Maren Toor and Gina Tan. Credits: Gina Tan

Sponges and ascidians are ancient organisms and very diverse with 9,144 and 3000 species, respectively. They are strong space competitors, and both have complex interactions with other organisms. Many new species from both groups are being discovered in the recent years but ecological information about sponges and particularly ascidians is very limited especially in tropical areas. Absences in baselines about ecological information limit our ability to detect temporal and spatial changes in the substrata and the species responsible of those changes.

Las esponjas y ascidias son organismos antiquisimos y muy  diversos con 9,144 y 3000 species respectivamente. Son competidores fuertes y tienen interaciones complejas con otros organismos. Varias especies de ambos grupos se han descubierto en los últimos años pero la información relevante sobre la ecología de las esponjas y especialmente de las ascidias es bastante limitada en las zonas tropicales. La ausencia de estas líneas base limita nuestra habilidad para detectar cambios temporales y espaciales en el sustrato e identificar las especies que ocasionan estos cambios.


Figure 2. Global patterns of species richness of sponges (top) and ascidians (bottom) from Van Soest et al, 2012 and Shenkar et al 2010.

We will conduct a series of activities to gain clues about how sponges and ascidians interact with other organisms and particularly with coral reefs. We will aim to detect whether sponges and ascidians overgrow corals, conduct some activities removing them from the substrata and assessing the responses of fish to these changes

Nuestro equipo ejecutará una serie de actividades para obtener pistas sobre como las esponjas y ascidias interactuan con otros organimos y especialmente con arrecifes de coral. Nuestro objetivo es determinar si las ascidias y esponjas crecen sobre los corales y conducir actividades de remoción de esponjas y ascidias para evaluar la respuesta de los peces a estos cambios.

gina y saul

Figure 3. Ascidians removal process at Otto´s Reef, Kimbe Bay. Credits: M. Toor 


Figure 4. Substrata cover assessment in inshore reefs, Kimbe Bay.

Figura 4.Evaluación de la cobertura de sustrato, en arrecifes cercanos a la costa, Bahia de Kimbe. Credits: G. Tan

2 thoughts on “Ascidians and sponges… here we go!

  1. Hello! This sounds like a very important research since there does not seem to be much information about the ecology of these species in your area of investigation. To address this, how many reefs are you surveying and to which extend to they differ from each other, if at all? Thank you!

  2. We are working in Papua New Guinea, Kimbe Bay and we focus on 6 reefs, many of them are quite similar but one has a steep wall or slope were the diversity of sponges is amazing. I will try to share a map soon, keep an eye on the blog.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s