Sustainable development of resources begins with understanding the environments where they are found and how exploitation may alter these environments. Unfortunately, the current state of available data in the deep sea is not adequate to answer even basic questions on the environments there such as the number of species present in a given region or the distribution and connectedness of most animals. There is a timely need to fill these gaps in knowledge to help guide commercial deep-sea mining activities which look likely in the near future. This chapter will explore the many difficulties with combining deep-sea mining datasets as well as several larger issues with deep-sea data in general that have contributed to these problems, focusing largely on ecological metazoan data. Problems that will be explored include general constraints in deep-sea work, spatial gaps in data collection, a lack of time-series datasets, inconsistencies with sample collection/processing, taxonomic identification issues, openness of available data, and our general lack of understanding of mining impacts. The discussion of data needs will include some possible solutions to each problem through lessons learned from previous studies on polymetallic nodules, seafloor massive sulfides, and cobalt crusts, specifically ecological datasets. Although a general refrain for the lack of deep-sea knowledge is more data, this chapter aims to provide more concrete and detailed solutions on how to use currently available data to their fullest and collect new datasets better capable of addressing questions around deep-sea mining impacts.